diff --git a/live/filters/__init__.py b/live/filters/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/live/filters/toxicity.py b/live/filters/toxicity.py
new file mode 100644
index 0000000..0b38000
--- /dev/null
+++ b/live/filters/toxicity.py
@@ -0,0 +1,116 @@
+"""
+Pre-trade toxicity filter — blocks quoting when market is adversarially informed.
+
+Uses VPIN and flow toxicity metrics from microstructure module to
+determine whether to quote, reduce size, or go flat.
+"""
+
+from __future__ import annotations
+
+from collections import deque
+from typing import Optional
+
+
+class ToxicityFilter:
+    """VPIN-based flow toxicity filter for market-making.
+
+    Monitors trade flow and order book to detect informed trading.
+    Blocks or reduces quoting when toxicity crosses thresholds.
+
+    Usage:
+        tf = ToxicityFilter()
+        tf.update_trade(buy_vol=0.1, sell_vol=0.05)
+        decision = tf.check()
+        if decision["allow_quoting"]:
+            size_mult = decision["size_multiplier"]
+    """
+
+    def __init__(
+        self,
+        vpin_threshold: float = 0.3,
+        vpin_alarm: float = 0.5,
+        vpin_window: int = 50,
+        volume_bucket_size: float = 1.0,
+        size_reduction_steps: int = 5,
+    ):
+        self._threshold = vpin_threshold
+        self._alarm = vpin_alarm
+        self._window = vpin_window
+        self._bucket_size = volume_bucket_size
+        self._steps = size_reduction_steps
+
+        self._buy_vol: deque[float] = deque(maxlen=5000)
+        self._sell_vol: deque[float] = deque(maxlen=5000)
+        self._current_vpin: float = 0.0
+        self._last_obi: float = 0.0
+        self._trade_count: int = 0
+
+    def update_trade(self, buy_vol: float, sell_vol: float):
+        """Feed a classified trade volume observation."""
+        self._buy_vol.append(buy_vol)
+        self._sell_vol.append(sell_vol)
+        self._trade_count += 1
+
+    def update_book_imbalance(self, obi: float):
+        """Feed current order-book imbalance."""
+        self._last_obi = obi
+
+    def compute(self):
+        """Recompute VPIN from accumulated volume data."""
+        from microstructure.toxicity import compute_vpin
+        result = compute_vpin(
+            list(self._buy_vol),
+            list(self._sell_vol),
+            volume_bucket_size=self._bucket_size,
+            n_buckets=self._window,
+        )
+        self._current_vpin = result.get("vpin_value", 0.0)
+
+    def check(self) -> dict:
+        """Evaluate current toxicity state.
+
+        Returns:
+            allow_quoting:  whether to quote at all
+            size_multiplier: fraction of base size to quote (1.0 = full, 0.0 = none)
+            vpin: current VPIN
+            obi: current OBI
+            reason: explanation if blocked/reduced
+        """
+        self.compute()
+        v = self._current_vpin
+
+        if v >= self._alarm:
+            return {
+                "allow_quoting": False,
+                "size_multiplier": 0.0,
+                "vpin": round(v, 4),
+                "obi": round(self._last_obi, 4),
+                "reason": f"VPIN {v:.3f} >= alarm {self._alarm}",
+            }
+
+        if v >= self._threshold:
+            reduction = (v - self._threshold) / (self._alarm - self._threshold)
+            size = max(0.0, 1.0 - reduction)
+            return {
+                "allow_quoting": size > 0.0,
+                "size_multiplier": round(size, 2),
+                "vpin": round(v, 4),
+                "obi": round(self._last_obi, 4),
+                "reason": f"VPIN {v:.3f} >= threshold {self._threshold}",
+            }
+
+        return {
+            "allow_quoting": True,
+            "size_multiplier": 1.0,
+            "vpin": round(v, 4),
+            "obi": round(self._last_obi, 4),
+            "reason": "ok",
+        }
+
+    @property
+    def vpin(self) -> float:
+        return self._current_vpin
+
+    @property
+    def trade_count(self) -> int:
+        return self._trade_count
diff --git a/live/makers/__init__.py b/live/makers/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/live/makers/hl_btc_eth.py b/live/makers/hl_btc_eth.py
new file mode 100644
index 0000000..b87fb49
--- /dev/null
+++ b/live/makers/hl_btc_eth.py
@@ -0,0 +1,218 @@
+"""
+Hyperliquid BTC/ETH maker strategy with tight inventory limits.
+
+Uses Avellaneda-Stoikov optimal control from sim/maker.py,
+toxicity filter from live/filters/toxicity.py, and treasury
+from live/treasury.py for position/risk management.
+
+Designed for Phase 4 controlled deployment: post-only quotes,
+tight inventory caps, toxicity gating.
+"""
+
+from __future__ import annotations
+
+import time
+from typing import Optional
+
+from sim.maker import AvellanedaStoikovMaker, MakerConfig, Quote
+from sim.queue import QueueModel
+from live.filters.toxicity import ToxicityFilter
+from live.treasury import Treasury
+
+
+class HlMaker:
+    """Hyperliquid market maker for a single coin.
+
+    Lifecycle per tick:
+      1. observe(mid_price) — feed mid price for vol estimation
+      2. update_flow(buy_vol, sell_vol, obi) — feed trade flow for toxicity
+      3. quote() — get bid/ask quotes (or None if blocked)
+      4. record_fill(side, size, price, fee) — after exchange confirms fill
+
+    Usage:
+        maker = HlMaker("BTC", treasury=treasury, max_inventory=0.003)
+        maker.observe(50000.0)
+        maker.update_flow(buy_vol=0.1, sell_vol=0.05, obi=0.2)
+        quote = maker.quote()
+        if quote:
+            # place bid at quote.bid, ask at quote.ask on exchange
+            ...
+    """
+
+    def __init__(
+        self,
+        coin: str,
+        treasury: Treasury,
+        max_inventory: float = 0.003,
+        base_size: float = 0.0002,
+        gamma: float = 0.1,
+        k: float = 1.5,
+        tau_hours: float = 1.0,
+        min_spread_bps: float = 1.0,
+        max_spread_bps: float = 15.0,
+        vpin_threshold: float = 0.3,
+        vpin_alarm: float = 0.5,
+        skew_factor: float = 0.3,
+    ):
+        self.coin = coin.upper()
+        self._treasury = treasury
+        self._max_inventory = max_inventory
+        self._base_size = base_size
+        self._skew_factor = skew_factor
+
+        self._maker = AvellanedaStoikovMaker(
+            MakerConfig(
+                gamma=gamma,
+                k=k,
+                tau=tau_hours,
+                min_spread_bps=min_spread_bps,
+                max_spread_bps=max_spread_bps,
+                base_size=base_size,
+                max_inventory=max_inventory,
+                skew_factor=skew_factor,
+            )
+        )
+
+        self._toxicity = ToxicityFilter(
+            vpin_threshold=vpin_threshold,
+            vpin_alarm=vpin_alarm,
+        )
+
+        self._mid_price: float = 0.0
+        self._best_bid: float = 0.0
+        self._best_ask: float = 0.0
+        self._elapsed_hours: float = 0.0
+        self._start_time: float = time.time()
+        self._last_quote: Optional[Quote] = None
+
+    def observe(self, mid_price: float):
+        """Feed a new mid price observation."""
+        self._mid_price = mid_price
+        self._elapsed_hours = (time.time() - self._start_time) / 3600.0
+        self._maker.observe(mid_price)
+        self._treasury.update_mark_price(self.coin, mid_price)
+
+    def update_book(self, best_bid: float, best_ask: float):
+        self._best_bid = best_bid
+        self._best_ask = best_ask
+
+    def update_flow(self, buy_vol: float, sell_vol: float, obi: float = 0.0):
+        """Feed trade flow and order-book imbalance for toxicity tracking."""
+        self._toxicity.update_trade(buy_vol, sell_vol)
+        self._toxicity.update_book_imbalance(obi)
+
+    def quote(self) -> Optional[Quote]:
+        """Generate the next set of quotes, or None if blocked."""
+        if self._treasury.is_halted():
+            return None
+        if self._mid_price <= 0:
+            return None
+
+        tox = self._toxicity.check()
+        if not tox["allow_quoting"]:
+            return None
+
+        size_mult = tox["size_multiplier"]
+
+        position = self._treasury.position(self.coin)
+        target_inv = 0.0  # neutral target
+
+        q = self._maker.quote_with_skew(
+            mid_price=self._mid_price,
+            inventory=position,
+            elapsed_hours=self._elapsed_hours,
+            target_inventory=target_inv,
+        )
+
+        # Scale sizes by toxicity multiplier
+        q.bid_size *= size_mult
+        q.ask_size *= size_mult
+
+        # Never cross the market
+        if self._best_bid > 0:
+            q.bid = round(min(q.bid, self._best_bid * 0.999), 2)
+        if self._best_ask > 0:
+            q.ask = round(max(q.ask, self._best_ask * 1.001), 2)
+
+        self._last_quote = q
+        return q
+
+    def record_fill(self, side: str, size: float, price: float, fee: float):
+        """Record a fill after exchange confirmation."""
+        pnl = 0.0
+        position = self._treasury.position(self.coin)
+        if (side == "sell" and position > 0) or (side == "buy" and position < 0):
+            pnl = size * (price - (self._mid_price))
+        self._treasury.record_fill(self.coin, side, size, price, fee, pnl)
+
+    def should_skip(self) -> bool:
+        """Check if we should skip quoting this tick."""
+        if self._treasury.is_halted():
+            return True
+        if self._treasury.position_size(self.coin) >= self._max_inventory:
+            return True
+        return False
+
+    @property
+    def last_quote(self) -> Optional[Quote]:
+        return self._last_quote
+
+    @property
+    def current_vpin(self) -> float:
+        return self._toxicity.vpin
+
+    def summary(self) -> dict:
+        return {
+            "coin": self.coin,
+            "mid": self._mid_price,
+            "position": self._treasury.position(self.coin),
+            "vpin": self._toxicity.vpin,
+            "sigma": self._maker.sigma,
+            "last_quote": {
+                "bid": self._last_quote.bid,
+                "ask": self._last_quote.ask,
+                "spread_bps": self._last_quote.spread_bps,
+            } if self._last_quote else None,
+        }
+
+
+class HlMakerPool:
+    """Manage multiple HlMaker instances across coins.
+
+    Provides unified interface for multi-coin market making with
+    shared treasury and coordinated quoting.
+    """
+
+    def __init__(self, treasury: Treasury, maker_config: dict | None = None):
+        self._treasury = treasury
+        self._maker_config = maker_config or {}
+        self._makers: dict[str, HlMaker] = {}
+
+    def add_maker(self, coin: str, max_inventory: float = 0.003, **kwargs) -> HlMaker:
+        cfg = dict(self._maker_config)
+        cfg.update(kwargs)
+        maker = HlMaker(coin=coin, treasury=self._treasury, max_inventory=max_inventory, **cfg)
+        self._makers[coin.upper()] = maker
+        return maker
+
+    def get(self, coin: str) -> Optional[HlMaker]:
+        return self._makers.get(coin.upper())
+
+    def observe_all(self, mid_prices: dict[str, float]):
+        for coin, price in mid_prices.items():
+            maker = self._makers.get(coin.upper())
+            if maker:
+                maker.observe(price)
+
+    def quote_all(self) -> dict[str, Optional[Quote]]:
+        return {coin: maker.quote() for coin, maker in self._makers.items()}
+
+    def summary(self) -> dict:
+        return {
+            coin: maker.summary()
+            for coin, maker in self._makers.items()
+        }
+
+    @property
+    def makers(self) -> dict[str, HlMaker]:
+        return self._makers
diff --git a/live/monitors/__init__.py b/live/monitors/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/live/monitors/cross_venue.py b/live/monitors/cross_venue.py
new file mode 100644
index 0000000..56c0133
--- /dev/null
+++ b/live/monitors/cross_venue.py
@@ -0,0 +1,120 @@
+"""
+Cross-venue lead-lag monitor.
+
+Detects when one exchange leads another in price discovery.
+Used for informational purposes only in Phase 4 — no auto-trading.
+"""
+
+from __future__ import annotations
+
+from collections import deque
+from typing import Optional
+
+import numpy as np
+
+
+class CrossVenueMonitor:
+    """Monitor price lead-lag relationships between exchanges.
+
+    Tracks mid prices across venues and computes cross-correlation
+    and lead-lag structure. Can detect when Hyperliquid follows
+    Binance or vice versa.
+
+    Usage:
+        monitor = CrossVenueMonitor(pairs=[("hl", "binance")], window=100)
+        monitor.update("hl", "BTC", 50000.0)
+        monitor.update("binance", "BTC", 50000.5)
+        result = monitor.lead_lag("BTC")
+    """
+
+    def __init__(
+        self,
+        pairs: list[tuple[str, str]] | None = None,
+        window: int = 100,
+        max_lag: int = 10,
+    ):
+        self._window = window
+        self._max_lag = max_lag
+        self._pairs = pairs or [("hl", "binance"), ("hl", "bybit"), ("hl", "okx")]
+
+        # venue → coin → deque of mid prices
+        self._prices: dict[str, dict[str, deque[float]]] = {}
+        self._timestamps: dict[str, dict[str, deque[float]]] = {}
+
+    def update(self, venue: str, coin: str, price: float, timestamp: float):
+        """Record a mid price observation from a venue."""
+        v = venue.lower()
+        c = coin.upper()
+        self._prices.setdefault(v, {}).setdefault(c, deque(maxlen=self._window)).append(price)
+        self._timestamps.setdefault(v, {}).setdefault(c, deque(maxlen=self._window)).append(timestamp)
+
+    def lead_lag(self, coin: str, venue_a: str = "hl", venue_b: str = "binance") -> dict | None:
+        """Determine which venue leads by cross-correlation at various lags.
+
+        Returns {leading_venue: str, max_correlation: float, lag: int}
+        Negative lag = venue_a leads, positive lag = venue_b leads.
+        """
+        prices_a = list(self._prices.get(venue_a.lower(), {}).get(coin.upper(), []))
+        prices_b = list(self._prices.get(venue_b.lower(), {}).get(coin.upper(), []))
+
+        min_len = min(len(prices_a), len(prices_b))
+        if min_len < self._max_lag + 2:
+            return None
+
+        a = np.array(prices_a[-min_len:])
+        b = np.array(prices_b[-min_len:])
+
+        best_corr = -1.0
+        best_lag = 0
+
+        for lag in range(-self._max_lag, self._max_lag + 1):
+            if lag < 0:
+                corr = np.corrcoef(a[-lag:], b[:lag])[0, 1] if lag < 0 else 0
+            elif lag > 0:
+                corr = np.corrcoef(a[:min_len - lag], b[lag:])[0, 1]
+            else:
+                corr = np.corrcoef(a, b)[0, 1]
+
+            if not np.isnan(corr) and abs(corr) > abs(best_corr):
+                best_corr = float(corr)
+                best_lag = lag
+
+        return {
+            "leading_venue": venue_a if best_lag < 0 else venue_b if best_lag > 0 else "none",
+            "correlation": round(best_corr, 4),
+            "lag": best_lag,
+            "samples": min_len,
+        }
+
+    def spot_premium(self, coin: str, venue: str = "hl", spot_venue: str = "binance") -> dict | None:
+        """Compute the premium of venue over spot (basis proxy)."""
+        v = self._prices.get(venue.lower(), {}).get(coin.upper())
+        sv = self._prices.get(spot_venue.lower(), {}).get(coin.upper())
+        if not v or not sv:
+            return None
+
+        perp = v[-1]
+        spot = sv[-1]
+        basis_bps = (perp - spot) / spot * 10000 if spot > 0 else 0
+
+        return {
+            "venue": venue,
+            "spot_venue": spot_venue,
+            "perp_price": perp,
+            "spot_price": spot,
+            "basis_bps": round(basis_bps, 2),
+        }
+
+    def summary(self, coin: str) -> dict:
+        """Summary for a given coin across all venues."""
+        result = {}
+        for va, vb in self._pairs:
+            ll = self.lead_lag(coin, va, vb)
+            if ll:
+                result[f"{va}_{vb}"] = ll
+
+        premium = self.spot_premium(coin)
+        if premium:
+            result["premium"] = premium
+
+        return result
diff --git a/live/monitors/funding_basis.py b/live/monitors/funding_basis.py
new file mode 100644
index 0000000..68f0ff0
--- /dev/null
+++ b/live/monitors/funding_basis.py
@@ -0,0 +1,99 @@
+"""
+Funding and basis carry monitor.
+
+Tracks funding rates across Hyperliquid and estimates carry
+trade profitability. Signals when funding arbitrage is attractive.
+
+Phase 4: informational only — no automated trading.
+"""
+
+from __future__ import annotations
+
+from collections import deque
+from typing import Optional
+
+from microstructure.funding import (
+    funding_regime,
+    funding_predictability,
+    funding_carry_pnl,
+)
+
+
+class FundingBasisMonitor:
+    """Monitor funding rates and carry trade opportunities.
+
+    Usage:
+        monitor = FundingBasisMonitor()
+        monitor.update_funding("BTC", 0.0001)
+        monitor.update_spot("BTC", 50000.0)
+        monitor.update_perp("BTC", 50005.0)
+        result = monitor.signal("BTC")
+    """
+
+    def __init__(
+        self,
+        funding_window: int = 1440,  # 24h at 1 sample/min
+        samples_per_hour: int = 60,
+    ):
+        self._samples_per_hour = samples_per_hour
+        self._funding: dict[str, deque[float]] = {}
+        self._perp_prices: dict[str, deque[float]] = {}
+        self._spot_prices: dict[str, deque[float]] = {}
+        self._window = funding_window
+
+    def update_funding(self, coin: str, rate: float):
+        """Record an hourly funding rate."""
+        self._funding.setdefault(coin.upper(), deque(maxlen=self._window)).append(rate)
+
+    def update_perp(self, coin: str, price: float):
+        self._perp_prices.setdefault(coin.upper(), deque(maxlen=self._window)).append(price)
+
+    def update_spot(self, coin: str, price: float):
+        self._spot_prices.setdefault(coin.upper(), deque(maxlen=self._window)).append(price)
+
+    def signal(self, coin: str) -> dict:
+        """Generate funding/basis signal for a coin."""
+        c = coin.upper()
+        funding_list = list(self._funding.get(c, []))
+        perp_list = list(self._perp_prices.get(c, []))
+        spot_list = list(self._spot_prices.get(c, []))
+
+        if not funding_list:
+            return {"signal": "insufficient_data", "action": "none"}
+
+        regime = funding_regime(funding_list, window_hours=min(24, len(funding_list) // self._samples_per_hour),
+                               n_samples_per_hour=self._samples_per_hour)
+        predictability = funding_predictability(funding_list)
+
+        basis = None
+        if perp_list and spot_list:
+            from microstructure.funding import basis_spread
+            basis = basis_spread(perp_list, spot_list)
+
+        carry = funding_carry_pnl(
+            funding_list,
+            position_size=1.0,
+            mark_prices=perp_list if perp_list else None,
+            n_samples_per_hour=self._samples_per_hour,
+        )
+
+        regime_name = regime.get("regime", "unknown")
+        action = "none"
+
+        if regime_name in ("high_positive",) and predictability.get("is_momentum"):
+            action = "consider_short"  # shorts earn positive funding
+        elif regime_name in ("high_negative",) and predictability.get("is_momentum"):
+            action = "consider_long"
+
+        return {
+            "signal": regime_name,
+            "action": action,
+            "funding_mean_annual_pct": regime.get("mean_annual_pct", 0),
+            "momentum": predictability.get("momentum_strength", 0),
+            "carry_cumulative_pnl": carry.get("cumulative_pnl", 0),
+            "basis_current_bps": basis.get("current_basis_bps", 0) if basis else 0,
+            "basis_mean_bps": basis.get("mean_basis_bps", 0) if basis else 0,
+        }
+
+    def summary(self) -> dict:
+        return {coin: self.signal(coin) for coin in self._funding}
diff --git a/live/monitors/liq_risk.py b/live/monitors/liq_risk.py
new file mode 100644
index 0000000..440167e
--- /dev/null
+++ b/live/monitors/liq_risk.py
@@ -0,0 +1,109 @@
+"""
+Liquidation risk overlay.
+
+Monitors current positions, mark prices, and computes liquidation
+distance. Warns when positions approach liquidation threshold.
+
+Integrates with live/treasury.py for position tracking.
+"""
+
+from __future__ import annotations
+
+from typing import Optional
+
+from live.treasury import Treasury
+
+
+class LiquidationRiskOverlay:
+    """Liquidation risk monitor for open positions.
+
+    Usage:
+        overlay = LiquidationRiskOverlay(treasury=treasury)
+        status = overlay.check("BTC")
+        if status["warning"]:
+            # reduce position or add margin
+    """
+
+    def __init__(
+        self,
+        treasury: Treasury,
+        warning_threshold_pct: float = 10.0,
+        danger_threshold_pct: float = 5.0,
+        critical_threshold_pct: float = 2.5,
+    ):
+        self._treasury = treasury
+        self._warning = warning_threshold_pct
+        self._danger = danger_threshold_pct
+        self._critical = critical_threshold_pct
+
+    def check(self, coin: str) -> dict:
+        """Check liquidation safety for a specific coin."""
+        distance = self._treasury.liquidation_distance(coin.upper())
+
+        if distance >= self._warning or distance >= 1e9:
+            level = "safe"
+        elif distance >= self._danger:
+            level = "warning"
+        elif distance >= self._critical:
+            level = "danger"
+        else:
+            level = "critical"
+
+        return {
+            "coin": coin.upper(),
+            "level": level,
+            "distance_pct": round(min(distance, 999999), 2),
+            "position": self._treasury.position(coin.upper()),
+            "warning": level in ("warning", "danger", "critical"),
+            "needs_action": level == "critical",
+        }
+
+    def check_all(self) -> dict[str, dict]:
+        positions = self._treasury.all_positions
+        return {coin: self.check(coin) for coin, pos in positions.items() if abs(pos) > 0}
+
+    def pnl_at_liquidation(self, coin: str) -> float:
+        """Estimate realized PnL if position reaches liquidation price."""
+        pos = self._treasury._positions.get(coin.upper())
+        if not pos:
+            return 0.0
+
+        entry = pos["entry_px"]
+        size = pos["size"]
+        side = pos["side"]
+
+        liq_price = self._treasury._liquidation.liquidation_price(
+            entry, size, side, self._treasury.equity
+        )
+
+        if side == "buy":
+            return size * (liq_price - entry)
+        else:
+            return size * (entry - liq_price)
+
+    def recommended_action(self, coin: str) -> str:
+        """Recommend action based on liquidation distance."""
+        status = self.check(coin)
+        level = status["level"]
+
+        if level == "safe":
+            return "none"
+        elif level == "warning":
+            return "reduce_position_25pct"
+        elif level == "danger":
+            return "reduce_position_50pct"
+        else:
+            return "close_all"
+
+    def summary(self) -> dict:
+        return {
+            "positions": self.check_all(),
+            "worst_case": min(
+                (self.check(c)["distance_pct"] for c in self._treasury.all_positions),
+                default=float("inf")
+            ),
+            "any_critical": any(
+                self.check(c)["level"] == "critical"
+                for c in self._treasury.all_positions
+            ),
+        }
diff --git a/live/treasury.py b/live/treasury.py
new file mode 100644
index 0000000..3ee0c2e
--- /dev/null
+++ b/live/treasury.py
@@ -0,0 +1,255 @@
+"""
+Central treasury — position/capital limits, circuit breakers, PnL stops.
+
+Single source of truth for all risk constraints in live trading.
+Integrates with sim/constraints.py for the constraint logic and adds
+live-specific bookkeeping.
+"""
+
+from __future__ import annotations
+
+import time
+from typing import Optional
+
+from sim.constraints import (
+    InventoryConstraint,
+    FundingConstraint,
+    FeeSchedule,
+    LiquidationRisk,
+    CircuitBreaker,
+)
+
+
+class Treasury:
+    """Central risk and capital management for live trading.
+
+    Tracks:
+      - Current positions per asset
+      - Realized and unrealized PnL
+      - Daily trade counts
+      - Circuit breaker state
+      - Fee budget consumption
+
+    Usage:
+        treasury = Treasury(initial_equity=10000.0)
+        ok = treasury.can_open("BTC", side="buy", size=0.001, mark_price=50000.0)
+        treasury.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0)
+    """
+
+    def __init__(
+        self,
+        initial_equity: float = 10000.0,
+        max_position_per_asset: float = 0.005,
+        max_net_exposure: float = 0.01,
+        max_daily_trades: int = 500,
+        max_drawdown_pct: float = -10.0,
+        max_toxic_rate: float = 0.4,
+        cooldown_seconds: float = 300.0,
+        maker_fee_pct: float = 0.0002,
+        taker_fee_pct: float = 0.0005,
+        maintenance_margin_pct: float = 0.03,
+    ):
+        self._initial_equity = initial_equity
+        self._realized_pnl: float = 0.0
+        self._fees_paid: float = 0.0
+        self._daily_trades: int = 0
+        self._toxic_fills: int = 0
+        self._api_errors: int = 0
+
+        # Positions tracked as {coin: {"side": "long"|"short", "size": float, "entry_px": float}}
+        self._positions: dict[str, dict] = {}
+        self._mark_prices: dict[str, float] = {}
+
+        self._circuit_breaker = CircuitBreaker(
+            max_drawdown_pct=max_drawdown_pct,
+            max_daily_trades=max_daily_trades,
+            max_toxic_rate=max_toxic_rate,
+            cooldown_seconds=cooldown_seconds,
+        )
+
+        self._inventory = InventoryConstraint(
+            max_long=max_position_per_asset,
+            max_short=max_position_per_asset,
+            max_net_exposure=max_net_exposure,
+        )
+
+        self._fees = FeeSchedule(maker_fee_pct=maker_fee_pct, taker_fee_pct=taker_fee_pct)
+        self._funding = FundingConstraint()
+        self._liquidation = LiquidationRisk(maintenance_margin_pct=maintenance_margin_pct)
+
+        self._halted: bool = False
+        self._halt_reason: str = ""
+        self._halted_at: float = 0.0
+        self._session_start: float = time.time()
+
+    # ── Position management ──────────────────────────────────
+
+    def can_open(self, coin: str, side: str, size: float, mark_price: float) -> dict:
+        """Check whether a new position can be opened.
+
+        Returns {allowed: bool, reason: str, fee_estimate: float}
+        """
+        if self._halted:
+            return {"allowed": False, "reason": self._halt_reason, "fee_estimate": 0.0}
+
+        pos = self._positions.get(coin.upper(), {})
+        current_size = pos.get("size", 0.0) if pos.get("side") == side else -(pos.get("size", 0.0))
+        new_size = current_size + size
+
+        limits = self._inventory.check(
+            max(0.0, new_size) if side == "buy" else max(0.0, current_size),
+            max(0.0, -new_size) if side == "sell" else max(0.0, -current_size),
+        )
+
+        if not limits["long_ok"]:
+            return {"allowed": False, "reason": "long limit exceeded", "fee_estimate": 0.0}
+        if not limits["short_ok"]:
+            return {"allowed": False, "reason": "short limit exceeded", "fee_estimate": 0.0}
+
+        fee = self._fees.maker_fee(size * mark_price)
+        return {"allowed": True, "reason": "ok", "fee_estimate": round(fee, 6)}
+
+    def record_fill(self, coin: str, side: str, size: float, price: float, fee: float, pnl: float = 0.0):
+        """Record a filled trade."""
+        c = coin.upper()
+        pos = self._positions.get(c)
+
+        is_close = pos and pos.get("side") != side
+        if is_close:
+            self._realized_pnl += pnl
+            pos["size"] -= size
+            if pos["size"] <= 1e-10:
+                del self._positions[c]
+        else:
+            if not pos:
+                self._positions[c] = {"side": side, "size": size, "entry_px": price}
+            else:
+                total = pos["size"] + size
+                pos["entry_px"] = (pos["entry_px"] * pos["size"] + price * size) / total if total > 0 else price
+                pos["size"] = total
+
+        self._fees_paid += fee
+        self._daily_trades += 1
+
+        self._check_breakers()
+
+    def record_toxic_fill(self):
+        self._toxic_fills += 1
+
+    def record_api_error(self):
+        self._api_errors += 1
+
+    def update_mark_price(self, coin: str, price: float):
+        self._mark_prices[coin.upper()] = price
+
+    # ── Position queries ─────────────────────────────────────
+
+    def position(self, coin: str) -> float:
+        """Signed position (positive = long)."""
+        pos = self._positions.get(coin.upper(), {})
+        raw = pos.get("size", 0.0)
+        return raw if pos.get("side") == "buy" else -raw
+
+    def position_size(self, coin: str) -> float:
+        """Absolute position size."""
+        return abs(self.position(coin))
+
+    @property
+    def all_positions(self) -> dict[str, float]:
+        return {c: self.position(c) for c in self._positions}
+
+    @property
+    def net_exposure(self) -> float:
+        return sum(abs(p) for p in self.all_positions.values())
+
+    # ── PnL ──────────────────────────────────────────────────
+
+    def unrealized_pnl(self) -> float:
+        pnl = 0.0
+        for coin, pos in self._positions.items():
+            mark = self._mark_prices.get(coin, pos.get("entry_px", 0))
+            if pos["side"] == "buy":
+                pnl += pos["size"] * (mark - pos["entry_px"])
+            else:
+                pnl += pos["size"] * (pos["entry_px"] - mark)
+        return round(pnl, 4)
+
+    def total_pnl(self) -> float:
+        return self._realized_pnl + self.unrealized_pnl() - self._fees_paid
+
+    def pnl_pct(self) -> float:
+        return self.total_pnl() / self._initial_equity * 100 if self._initial_equity > 0 else 0
+
+    @property
+    def equity(self) -> float:
+        return self._initial_equity + self.total_pnl()
+
+    # ── Liquidation risk ─────────────────────────────────────
+
+    def liquidation_distance(self, coin: str) -> float:
+        """Percentage distance to liquidation."""
+        pos = self._positions.get(coin.upper())
+        if not pos:
+            return float("inf")
+
+        mark = self._mark_prices.get(coin.upper(), pos["entry_px"])
+        liq = self._liquidation.liquidation_price(
+            entry_price=pos["entry_px"],
+            size=pos["size"],
+            position_side=pos["side"],
+            wallet_balance=self.equity,
+        )
+        return self._liquidation.distance_to_liquidation_pct(mark, liq, pos["side"])
+
+    def is_liquidation_safe(self, coin: str, threshold_pct: float = 5.0) -> bool:
+        return self.liquidation_distance(coin) >= threshold_pct
+
+    # ── Circuit breaker ──────────────────────────────────────
+
+    def _check_breakers(self):
+        if self._halted:
+            return
+        toxic_rate = self._toxic_fills / max(self._daily_trades, 1)
+        result = self._circuit_breaker.evaluate({
+            "pnl_pct": round(self.pnl_pct(), 2),
+            "daily_trades": self._daily_trades,
+            "toxic_rate": toxic_rate,
+            "api_errors": self._api_errors,
+        })
+        if result.get("tripped"):
+            self._halted = True
+            self._halt_reason = result.get("reason", "unknown")
+            self._halted_at = time.time()
+
+    def is_halted(self) -> bool:
+        if self._halted:
+            elapsed = time.time() - self._halted_at
+            if elapsed > self._circuit_breaker.cooldown_seconds:
+                self._halted = False
+                self._halt_reason = ""
+                self._daily_trades = 0
+                self._toxic_fills = 0
+        return self._halted
+
+    @property
+    def halt_reason(self) -> str:
+        return self._halt_reason
+
+    # ── Stats ────────────────────────────────────────────────
+
+    def summary(self) -> dict:
+        return {
+            "equity": round(self.equity, 2),
+            "realized_pnl": round(self._realized_pnl, 4),
+            "unrealized_pnl": self.unrealized_pnl(),
+            "total_pnl": self.total_pnl(),
+            "pnl_pct": round(self.pnl_pct(), 2),
+            "fees_paid": round(self._fees_paid, 4),
+            "daily_trades": self._daily_trades,
+            "toxic_fills": self._toxic_fills,
+            "api_errors": self._api_errors,
+            "positions": {c: round(v, 6) for c, v in self.all_positions.items()},
+            "net_exposure": round(self.net_exposure, 6),
+            "halted": self._halted,
+            "uptime_hours": round((time.time() - self._session_start) / 3600, 1),
+        }
diff --git a/tests/test_live_filters.py b/tests/test_live_filters.py
new file mode 100644
index 0000000..192efa8
--- /dev/null
+++ b/tests/test_live_filters.py
@@ -0,0 +1,38 @@
+"""
+Tests for live/filters/toxicity.py — pre-trade toxicity filter.
+"""
+from live.filters.toxicity import ToxicityFilter
+
+
+class TestToxicityFilter:
+    def test_initial_state_allows_quoting(self):
+        tf = ToxicityFilter()
+        result = tf.check()
+        assert result["allow_quoting"]
+        assert result["size_multiplier"] == 1.0
+
+    def test_balanced_flow_keeps_quoting(self):
+        tf = ToxicityFilter()
+        for _ in range(200):
+            tf.update_trade(buy_vol=1.0, sell_vol=1.0)
+        result = tf.check()
+        assert result["allow_quoting"]
+
+    def test_imbalanced_flow_reduces_or_blocks(self):
+        tf = ToxicityFilter(vpin_threshold=0.2, vpin_alarm=0.3, volume_bucket_size=1.0, vpin_window=10)
+        for _ in range(200):
+            tf.update_trade(buy_vol=3.0, sell_vol=1.0)
+        result = tf.check()
+        assert result["vpin"] >= 0
+
+    def test_book_imbalance_tracking(self):
+        tf = ToxicityFilter()
+        tf.update_book_imbalance(0.5)
+        result = tf.check()
+        assert result["obi"] == 0.5
+
+    def test_trade_count_increments(self):
+        tf = ToxicityFilter()
+        tf.update_trade(0.1, 0.05)
+        tf.update_trade(0.2, 0.1)
+        assert tf.trade_count == 2
diff --git a/tests/test_live_maker.py b/tests/test_live_maker.py
new file mode 100644
index 0000000..c408487
--- /dev/null
+++ b/tests/test_live_maker.py
@@ -0,0 +1,86 @@
+"""
+Tests for live/makers/hl_btc_eth.py — HL maker strategy.
+"""
+from live.treasury import Treasury
+from live.makers.hl_btc_eth import HlMaker, HlMakerPool
+
+
+class TestHlMaker:
+    def test_initial_quote_returns_none(self):
+        t = Treasury(initial_equity=10000.0)
+        maker = HlMaker("BTC", treasury=t)
+        assert maker.quote() is None  # no mid price yet
+
+    def test_quote_after_observe(self):
+        t = Treasury(initial_equity=10000.0)
+        maker = HlMaker("BTC", treasury=t, base_size=0.001)
+        maker.observe(50000.0)
+        maker.update_book(49999.0, 50001.0)
+        q = maker.quote()
+        assert q is not None
+        assert q.bid < 50000.0 < q.ask
+        assert q.bid_size > 0
+        assert q.ask_size > 0
+
+    def test_quote_blocked_by_halte(self):
+        t = Treasury(initial_equity=10000.0, max_drawdown_pct=-1.0)
+        t._realized_pnl = -5000.0
+        t._fees_paid = 0
+        t._check_breakers()
+        maker = HlMaker("BTC", treasury=t)
+        maker.observe(50000.0)
+        assert maker.quote() is None
+
+    def test_should_skip_at_max_inventory(self):
+        t = Treasury(initial_equity=10000.0)
+        maker = HlMaker("BTC", treasury=t, max_inventory=0.001)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        maker.observe(50000.0)
+        assert maker.should_skip()
+
+    def test_record_fill_updates_treasury(self):
+        t = Treasury(initial_equity=10000.0)
+        maker = HlMaker("BTC", treasury=t)
+        maker.observe(50000.0)
+        maker.record_fill("buy", 0.001, 50000.0, 10.0)
+        assert t.position("BTC") == 0.001
+
+    def test_quote_never_crosses_book(self):
+        t = Treasury(initial_equity=10000.0)
+        maker = HlMaker("BTC", treasury=t, base_size=0.001, gamma=0.5)
+        maker.observe(50000.0)
+        maker.update_book(49995.0, 50005.0)
+        for _ in range(20):
+            q = maker.quote()
+            if q:
+                assert q.bid <= 49995.0  # never above best bid
+                assert q.ask >= 50005.0  # never below best ask
+                assert q.bid < q.ask
+
+
+class TestHlMakerPool:
+    def test_add_and_get_makers(self):
+        t = Treasury(initial_equity=10000.0)
+        pool = HlMakerPool(treasury=t)
+        pool.add_maker("BTC", max_inventory=0.002)
+        pool.add_maker("ETH", max_inventory=0.01)
+        assert pool.get("BTC") is not None
+        assert pool.get("ETH") is not None
+        assert pool.get("SOL") is None
+
+    def test_observe_and_quote_all(self):
+        t = Treasury(initial_equity=10000.0)
+        pool = HlMakerPool(treasury=t)
+        maker_btc = pool.add_maker("BTC", max_inventory=0.002, base_size=0.001)
+        pool.observe_all({"BTC": 50000.0})
+        quotes = pool.quote_all()
+        assert "BTC" in quotes
+        assert quotes["BTC"] is not None
+
+    def test_summary(self):
+        t = Treasury(initial_equity=10000.0)
+        pool = HlMakerPool(treasury=t)
+        pool.add_maker("BTC", max_inventory=0.002)
+        pool.observe_all({"BTC": 50000.0})
+        s = pool.summary()
+        assert "BTC" in s
diff --git a/tests/test_live_monitors.py b/tests/test_live_monitors.py
new file mode 100644
index 0000000..b9ac327
--- /dev/null
+++ b/tests/test_live_monitors.py
@@ -0,0 +1,93 @@
+"""
+Tests for live/monitors — cross-venue, funding/basis, liquidation risk.
+"""
+from live.monitors.cross_venue import CrossVenueMonitor
+from live.monitors.funding_basis import FundingBasisMonitor
+from live.monitors.liq_risk import LiquidationRiskOverlay
+from live.treasury import Treasury
+
+
+class TestCrossVenueMonitor:
+    def test_update_and_lead_lag(self):
+        cm = CrossVenueMonitor(window=50, max_lag=5)
+        for i in range(50):
+            cm.update("hl", "BTC", 50000.0 + i * 10, float(i))
+            cm.update("binance", "BTC", 50000.0 + i * 10 + 2, float(i))
+        result = cm.lead_lag("BTC", "hl", "binance")
+        assert result is not None
+        assert "correlation" in result
+        assert "lag" in result
+
+    def test_spot_premium(self):
+        cm = CrossVenueMonitor()
+        for _ in range(10):
+            cm.update("hl", "BTC", 50005.0, 0)
+            cm.update("binance", "BTC", 50000.0, 0)
+        premium = cm.spot_premium("BTC")
+        assert premium is not None
+        assert premium["basis_bps"] > 0
+
+    def test_nonexistent_coin_returns_none(self):
+        cm = CrossVenueMonitor()
+        assert cm.lead_lag("XYZ", "hl", "binance") is None
+
+    def test_summary(self):
+        cm = CrossVenueMonitor()
+        for i in range(50):
+            cm.update("hl", "BTC", 50000.0 + i * 10, float(i))
+            cm.update("binance", "BTC", 50000.0 + i * 10, float(i))
+        s = cm.summary("BTC")
+        assert "hl_binance" in s
+
+
+class TestFundingBasisMonitor:
+    def test_initial_no_signal(self):
+        fm = FundingBasisMonitor()
+        result = fm.signal("BTC")
+        assert result["signal"] == "insufficient_data"
+
+    def test_signal_with_data(self):
+        fm = FundingBasisMonitor(funding_window=100, samples_per_hour=60)
+        for _ in range(200):
+            fm.update_funding("BTC", 0.00001)
+        result = fm.signal("BTC")
+        assert result["signal"] in ("neutral", "positive", "negative", "high_positive", "high_negative")
+        assert "funding_mean_annual_pct" in result
+
+    def test_basis_requires_spot_and_perp(self):
+        fm = FundingBasisMonitor()
+        for i in range(50):
+            fm.update_perp("BTC", 50005.0)
+            fm.update_spot("BTC", 50000.0)
+            fm.update_funding("BTC", 0.00001)
+        result = fm.signal("BTC")
+        assert result["basis_current_bps"] > 0
+
+
+class TestLiquidationRiskOverlay:
+    def test_safe_position(self):
+        t = Treasury(initial_equity=100000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        overlay = LiquidationRiskOverlay(treasury=t)
+        result = overlay.check("BTC")
+        assert result["level"] == "safe"
+
+    def test_no_position(self):
+        t = Treasury(initial_equity=10000.0)
+        overlay = LiquidationRiskOverlay(treasury=t)
+        result = overlay.check("BTC")
+        assert result["distance_pct"] > 1e5  # capped at 999999 for display
+
+    def test_recommended_action(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        overlay = LiquidationRiskOverlay(treasury=t)
+        assert overlay.recommended_action("BTC") == "none"
+
+    def test_summary(self):
+        t = Treasury(initial_equity=100000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        overlay = LiquidationRiskOverlay(treasury=t)
+        s = overlay.summary()
+        assert "positions" in s
+        assert "worst_case" in s
diff --git a/tests/test_live_treasury.py b/tests/test_live_treasury.py
new file mode 100644
index 0000000..40a3f67
--- /dev/null
+++ b/tests/test_live_treasury.py
@@ -0,0 +1,95 @@
+"""
+Tests for live/treasury.py — central treasury and risk management.
+"""
+from live.treasury import Treasury
+
+
+class TestTreasury:
+    def test_initial_equity(self):
+        t = Treasury(initial_equity=10000.0)
+        assert t.equity == 10000.0
+        assert t.total_pnl() == 0.0
+
+    def test_can_open_within_limits(self):
+        t = Treasury(initial_equity=10000.0, max_position_per_asset=0.005)
+        result = t.can_open("BTC", side="buy", size=0.001, mark_price=50000.0)
+        assert result["allowed"]
+
+    def test_cannot_open_exceed_inventory(self):
+        t = Treasury(initial_equity=10000.0, max_position_per_asset=0.002)
+        t.can_open("BTC", side="buy", size=0.001, mark_price=50000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        result = t.can_open("BTC", side="buy", size=0.0015, mark_price=50000.0)
+        assert not result["allowed"]
+
+    def test_record_fill_updates_position(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        assert t.position("BTC") == 0.001
+
+    def test_record_close_updates_pnl(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        t.record_fill("BTC", side="sell", size=0.001, price=50100.0, fee=10.0, pnl=100.0)
+        assert t.position("BTC") == 0.0
+        assert t.total_pnl() > 0
+
+    def test_unrealized_pnl(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        t.update_mark_price("BTC", 50200.0)
+        assert t.unrealized_pnl() > 0
+
+    def test_pnl_pct(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.1, price=50000.0, fee=0.1, pnl=0)
+        t.update_mark_price("BTC", 50200.0)  # 0.1 * 200 = $20 unrealized >> $0.10 fee
+        assert t.pnl_pct() > 0
+
+    def test_circuit_breaker_drawdown(self):
+        t = Treasury(initial_equity=10000.0, max_drawdown_pct=-1.0)
+        # Force large negative PnL
+        t._realized_pnl = -5000.0
+        t._fees_paid = 0
+        t._check_breakers()
+        assert t.is_halted()
+
+    def test_liquidation_distance(self):
+        t = Treasury(initial_equity=50000.0)
+        t.record_fill("BTC", side="buy", size=1.0, price=50000.0, fee=10.0, pnl=0)
+        dist = t.liquidation_distance("BTC")
+        assert dist > 0
+
+    def test_all_positions(self):
+        t = Treasury()
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        t.record_fill("ETH", side="sell", size=0.01, price=3000.0, fee=10.0, pnl=0)
+        positions = t.all_positions
+        assert positions["BTC"] == 0.001
+        assert positions["ETH"] == -0.01
+
+    def test_net_exposure(self):
+        t = Treasury()
+        t.record_fill("BTC", side="buy", size=0.002, price=50000.0, fee=10.0, pnl=0)
+        t.record_fill("ETH", side="buy", size=0.003, price=3000.0, fee=10.0, pnl=0)
+        assert t.net_exposure == 0.005
+
+    def test_summary(self):
+        t = Treasury(initial_equity=10000.0)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        s = t.summary()
+        assert "equity" in s
+        assert "pnl_pct" in s
+        assert "positions" in s
+        assert "BTC" in s["positions"]
+
+    def test_toxic_fill_tracking(self):
+        t = Treasury(initial_equity=10000.0, max_toxic_rate=0.1)
+        t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=0)
+        for _ in range(9):
+            t.record_fill("BTC", side="buy", size=0.001, price=50000.0, fee=10.0, pnl=-1.0)
+        t.record_toxic_fill()
+        t.record_toxic_fill()
+        t._check_breakers()
+        # 2/10 = 20% toxic > 10% threshold
+        assert t.is_halted()