diff --git a/backtests/vbt_runner.py b/backtests/vbt_runner.py
index 3c5fec4..0af57b3 100644
--- a/backtests/vbt_runner.py
+++ b/backtests/vbt_runner.py
@@ -35,12 +35,21 @@ RESULTS_DIR.mkdir(parents=True, exist_ok=True)
 # Strategy signal generators
 # ═══════════════════════════════════════════════════════════════
 
-def _generate_signals(strategy: str, data: dict[str, pd.DataFrame]) -> tuple[pd.Series, pd.Series]:
+def _generate_signals(strategy: str, data: dict[str, pd.DataFrame],
+                     params: dict | None = None) -> tuple[pd.Series, pd.Series]:
     """Generate entry/exit signals for a strategy from candle data.
 
     Returns (entries, exits) as boolean pandas Series.
     Each strategy uses the primary coin's close prices.
+
+    Params:
+      grid_mm: grid_levels, spacing_bps, rebalance_every
+      as_mm: gamma, k, tau, min_hold, max_hold, profit_target, stop_loss
+      obi: lookback, entry_threshold, exit_threshold
+      pairs: z_entry, z_exit, lookback
     """
+    if params is None:
+        params = {}
     main_coin = {"pairs": "ETH", "hurst_vpin": "BTC", "as_mm": "BTC",
                  "obi": "BTC", "grid_mm": "BTC", "composite_mm": "BTC",
                  "iceberg": "BTC", "funding_arb": "BTC", "momentum": "BTC",
@@ -142,14 +151,13 @@ def _generate_signals(strategy: str, data: dict[str, pd.DataFrame]) -> tuple[pd.
 
     elif strategy == "grid_mm":
         # Grid MM: simulate grid fills from candle high/low ranges
-        grid_levels = 10
-        grid_spacing_pct = 0.001
+        grid_levels = params.get("grid_levels", 10)
+        grid_spacing_pct = params.get("spacing_bps", 10) / 10000  # bps → decimal
+        rebalance = params.get("rebalance_every", 20)
 
         entries = pd.Series(False, index=close.index)
         exits = pd.Series(False, index=close.index)
-        # Track grid state per bar
-        grid_fills = 0
-        prev_entry = 0
+        fills_accumulated = 0
 
         for i in range(1, len(close)):
             mid = close.iloc[i]
@@ -164,10 +172,11 @@ def _generate_signals(strategy: str, data: dict[str, pd.DataFrame]) -> tuple[pd.
                 if high >= sell_px:
                     fills_this_bar += 1
             if fills_this_bar > 0:
+                fills_accumulated += fills_this_bar
                 entries.iloc[i] = True
-                # Exit after spread capture (next bar close)
-                if i + 1 < len(close):
-                    exits.iloc[i + 1] = True
+                # Exit after rebalance period
+                if i + rebalance < len(close):
+                    exits.iloc[i + rebalance] = True
 
     elif strategy == "composite_mm":
         # Composite: weighted ensemble of OBI + Hurst
@@ -314,6 +323,7 @@ class VBTBacktestRunner:
         limit: int = 5000,
         start_ms: int | None = None,
         end_ms: int | None = None,
+        params: dict | None = None,
     ) -> dict[str, Any] | None:
         """Fetch candles, generate signals, run VBT backtest, return metrics."""
         coins = self._get_coins(strategy)
@@ -332,7 +342,7 @@ class VBTBacktestRunner:
             logger.error("No candle data fetched for strategy: %s", strategy)
             return None
 
-        entries, exits = _generate_signals(strategy, data)
+        entries, exits = _generate_signals(strategy, data, params)
 
         primary = list(data.values())[0]
         close = primary["close"]
@@ -365,7 +375,7 @@ class VBTBacktestRunner:
             return self._empty_result(strategy, interval)
 
         stats = pf.stats()
-        result = self._extract_metrics(pf, stats, strategy, interval, len(close))
+        result = self._extract_metrics(pf, stats, strategy, interval, len(close), params)
 
         # Save equity curve
         eq_curve = pf.value().dropna()
@@ -448,7 +458,8 @@ class VBTBacktestRunner:
         }
         return coin_map.get(strategy, ["BTC"])
 
-    def _extract_metrics(self, pf, stats, strategy, interval, n_bars) -> dict:
+    def _extract_metrics(self, pf, stats, strategy, interval, n_bars,
+                         runtime_params=None) -> dict:
         from config.fee_tiers import compute_trade_fees, get_strategy_fee_model
 
         main_coin = self._get_coins(strategy)[0]
@@ -519,7 +530,7 @@ class VBTBacktestRunner:
             "profit_factor": round(float(stats.get("Profit Factor", 0)), 3),
             "expectancy": round(float(stats.get("Expectancy", 0)), 3),
             "trades": trades,
-            "params": _strategy_params(strategy),
+            "params": _strategy_params(strategy, runtime_params),
             "fee_info": fee_info,
         }
 
@@ -543,20 +554,23 @@ class VBTBacktestRunner:
         }
 
 
-def _strategy_params(strategy: str) -> dict:
+def _strategy_params(strategy: str, runtime_params: dict | None = None) -> dict:
     """Return the key parameters/coefficients for a strategy."""
-    params = {
+    base = {
         "pairs": {"z_entry": 1.5, "z_exit": 0.5, "lookback": 20, "type": "Stat Arb"},
         "hurst_vpin": {"hurst_entry": 0.55, "hurst_exit": 0.45, "vpin_threshold": 0.25, "vpin_window": 50, "hurst_window": 64, "type": "Directional"},
         "as_mm": {"gamma": 0.1, "sigma_dynamic": True, "inventory_skew": True, "type": "Market Making"},
         "obi": {"obi_lookback": 20, "obi_entry": 0.35, "obi_exit": 0.10, "type": "Reversal"},
-        "grid_mm": {"grid_levels": 10, "grid_spacing_pct": 0.1, "rebalance_every": 20, "type": "Market Making"},
+        "grid_mm": {"grid_levels": 10, "spacing_bps": 10, "rebalance_every": 20, "type": "Market Making"},
         "composite_mm": {"obi_weight": 0.30, "as_weight": 0.40, "hurst_weight": 0.30, "entry_score": 0.50, "type": "Ensemble"},
         "iceberg": {"vol_mult": 1.8, "min_consec": 3, "max_hold": 8, "type": "Momentum"},
         "momentum": {"bollinger_window": 20, "bollinger_std": 2.0, "type": "Momentum"},
         "mean_rev": {"vwap_window": 20, "deviation": 1.0, "type": "Reversal"},
     }
-    return params.get(strategy, {"type": "Unknown"})
+    result = base.get(strategy, {"type": "Unknown"})
+    if runtime_params:
+        result.update({k: v for k, v in runtime_params.items() if k in result})
+    return result
 
 
 def _generate_signals_sweep(
diff --git a/quant/optimizer.py b/quant/optimizer.py
new file mode 100644
index 0000000..0dc3682
--- /dev/null
+++ b/quant/optimizer.py
@@ -0,0 +1,280 @@
+"""
+Automated parameter walk-forward optimizer.
+
+Takes a strategy and parameter grid, runs IS/OOS walk-forward across
+N windows, picks the best parameter combo per window, and reports
+out-of-sample performance with statistical significance.
+
+Usage:
+    optimizer = ParamOptimizer(strategy='grid_mm', interval='1h')
+    optimizer.add_param('grid_levels', [5, 10, 20, 50])
+    optimizer.add_param('spacing_bps', [1, 2, 5, 10, 20, 50])
+    optimizer.add_param('rebalance_every', [5, 10, 20, 50])
+    report = optimizer.run(n_windows=4)
+    print(report.summary())
+"""
+
+from __future__ import annotations
+
+import itertools
+import logging
+import time
+from dataclasses import dataclass, field
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class ParamResult:
+    """Single parameter combo result."""
+    params: dict
+    sharpe: float
+    return_pct: float
+    trades: int
+    win_rate: float = 0.0
+
+    @property
+    def score(self) -> float:
+        """Composite score: Sharpe weighted by sqrt(trades) for robustness."""
+        return self.sharpe * (self.trades ** 0.5) if self.trades > 0 else -999.0
+
+
+@dataclass
+class WFParamWindow:
+    """Single walk-forward window with parameter optimization."""
+    window_idx: int
+    is_start: str
+    is_end: str
+    oos_start: str
+    oos_end: str
+    best_params: dict
+    is_sharpe: float
+    oos_sharpe: float
+    is_return_pct: float
+    oos_return_pct: float
+    oos_trades: int
+    is_trials: int = 0
+
+
+@dataclass
+class OptimizerReport:
+    """Complete parameter optimization walk-forward report."""
+    strategy: str
+    interval: str
+    n_windows: int
+    total_trials: int
+    windows: list[WFParamWindow] = field(default_factory=list)
+    elapsed_seconds: float = 0.0
+
+    @property
+    def consistency(self) -> float:
+        if not self.windows:
+            return 0.0
+        return sum(1 for w in self.windows if w.oos_sharpe > 0) / len(self.windows)
+
+    @property
+    def avg_oos_sharpe(self) -> float:
+        if not self.windows:
+            return 0.0
+        return sum(w.oos_sharpe for w in self.windows) / len(self.windows)
+
+    @property
+    def best_stable_params(self) -> dict | None:
+        """Find params that appear most frequently across windows."""
+        from collections import Counter
+        param_sigs = []
+        for w in self.windows:
+            sig = tuple(sorted(w.best_params.items()))
+            param_sigs.append(sig)
+        if not param_sigs:
+            return None
+        most_common = Counter(param_sigs).most_common(1)[0]
+        return dict(most_common[0])
+
+    def summary(self) -> dict:
+        return {
+            "strategy": self.strategy,
+            "interval": self.interval,
+            "n_windows": self.n_windows,
+            "total_trials": self.total_trials,
+            "consistency": round(self.consistency, 3),
+            "avg_oos_sharpe": round(self.avg_oos_sharpe, 3),
+            "stable_params": self.best_stable_params,
+            "elapsed_s": round(self.elapsed_seconds, 1),
+        }
+
+    def print(self):
+        for w in self.windows:
+            print(f'  W{w.window_idx}: {w.is_start}→{w.is_end}/{w.oos_start}→{w.oos_end}')
+            print(f'    Best params: {w.best_params}')
+            print(f'    IS: S={w.is_sharpe:.2f} ret={w.is_return_pct:.1f}% ({w.is_trials} trials)')
+            print(f'    OOS: S={w.oos_sharpe:.2f} ret={w.oos_return_pct:.1f}% ({w.oos_trades}t)')
+        print(f'  Consistency: {self.consistency:.1%}  Avg OOS Sharpe: {self.avg_oos_sharpe:.2f}')
+        if self.best_stable_params:
+            print(f'  Stable params: {self.best_stable_params}')
+
+
+class ParamOptimizer:
+    """Automated strategy parameter walk-forward optimizer."""
+
+    def __init__(
+        self,
+        strategy: str = "grid_mm",
+        interval: str = "1h",
+        coin: str = "BTC",
+        n_windows: int = 4,
+        fee_tier: int = 0,
+        staking_tier: str = "none",
+    ):
+        self._strategy = strategy
+        self._interval = interval
+        self._coin = coin
+        self._n_windows = n_windows
+        self._fee_tier = fee_tier
+        self._staking_tier = staking_tier
+        self._param_grid: dict[str, list] = {}
+
+    def add_param(self, name: str, values: list):
+        """Add a parameter to sweep."""
+        self._param_grid[name] = values
+
+    def _generate_combos(self) -> list[dict]:
+        """Generate all param combinations from the grid."""
+        if not self._param_grid:
+            return [{}]
+        keys = list(self._param_grid.keys())
+        combos = []
+        for values in itertools.product(*self._param_grid.values()):
+            combos.append(dict(zip(keys, values)))
+        return combos
+
+    def _optimize_is(self, is_start_ms: int, is_end_ms: int) -> ParamResult:
+        """Find best params on in-sample data."""
+        from backtests.vbt_runner import VBTBacktestRunner
+
+        best = ParamResult(params={}, sharpe=-999, return_pct=0, trades=0)
+        combos = self._generate_combos()
+
+        async_run_limit = 720
+        if self._interval == "1h":
+            async_run_limit = 720
+        elif self._interval == "4h":
+            async_run_limit = 180
+        elif self._interval == "1d":
+            async_run_limit = 30
+
+        for combo in combos:
+            try:
+                runner = VBTBacktestRunner(
+                    vip_tier=self._fee_tier, staking_tier=self._staking_tier
+                )
+                result = runner.run_strategy(
+                    strategy=self._strategy, interval=self._interval,
+                    limit=async_run_limit, start_ms=is_start_ms, end_ms=is_end_ms,
+                    params=combo,
+                )
+                if result:
+                    sh = result.get("sharpe", -999)
+                    ret = result.get("total_return_pct", 0)
+                    tr = len(result.get("trades", []))
+                    wr = result.get("win_rate", 0)
+                    candidate = ParamResult(params=combo, sharpe=sh, return_pct=ret, trades=tr, win_rate=wr)
+                    if candidate.score > best.score:
+                        best = candidate
+            except Exception:
+                pass
+
+        return best
+
+    def _test_oos(self, oos_start_ms: int, oos_end_ms: int, params: dict) -> ParamResult:
+        """Test params on out-of-sample data."""
+        from backtests.vbt_runner import VBTBacktestRunner
+
+        try:
+            runner = VBTBacktestRunner(
+                vip_tier=self._fee_tier, staking_tier=self._staking_tier
+            )
+            result = runner.run_strategy(
+                strategy=self._strategy, interval=self._interval,
+                limit=720, start_ms=oos_start_ms, end_ms=oos_end_ms,
+                params=params,
+            )
+            if result:
+                return ParamResult(
+                    params=params,
+                    sharpe=result.get("sharpe", 0),
+                    return_pct=result.get("total_return_pct", 0),
+                    trades=len(result.get("trades", [])),
+                    win_rate=result.get("win_rate", 0),
+                )
+        except Exception:
+            pass
+        return ParamResult(params=params, sharpe=0, return_pct=0, trades=0)
+
+    def run(self) -> OptimizerReport:
+        """Execute full walk-forward parameter optimization."""
+        from framework.data import HyperliquidDataProvider
+
+        start_time = time.time()
+
+        provider = HyperliquidDataProvider()
+        df = provider.fetch_candles(self._coin, interval=self._interval, limit=5000)
+
+        if df.empty or len(df) < 100:
+            return OptimizerReport(strategy=self._strategy, interval=self._interval,
+                                   n_windows=self._n_windows, total_trials=0)
+
+        total_bars = len(df)
+        window_size = total_bars // (self._n_windows + 1)
+        if window_size < 50:
+            return OptimizerReport(strategy=self._strategy, interval=self._interval,
+                                   n_windows=self._n_windows, total_trials=0)
+
+        total_trials = 0
+        report = OptimizerReport(
+            strategy=self._strategy, interval=self._interval,
+            n_windows=self._n_windows, total_trials=0,
+        )
+
+        n_combos = len(self._generate_combos())
+
+        for w in range(self._n_windows):
+            is_start_idx = w * window_size
+            is_end_idx = is_start_idx + window_size
+            oos_start_idx = is_end_idx
+            oos_end_idx = min(oos_start_idx + window_size, total_bars)
+
+            is_start_ms = int(df.index[is_start_idx].timestamp() * 1000)
+            is_end_ms = int(df.index[min(is_end_idx - 1, total_bars - 1)].timestamp() * 1000)
+            oos_start_ms = int(df.index[min(oos_start_idx, total_bars - 1)].timestamp() * 1000)
+            oos_end_ms = int(df.index[min(oos_end_idx - 1, total_bars - 1)].timestamp() * 1000)
+
+            is_start_ts = str(df.index[is_start_idx])[:10]
+            is_end_ts = str(df.index[min(is_end_idx - 1, total_bars - 1)])[:10]
+            oos_start_ts = str(df.index[min(oos_start_idx, total_bars - 1)])[:10]
+            oos_end_ts = str(df.index[min(oos_end_idx - 1, total_bars - 1)])[:10]
+
+            # IS optimization
+            best_is = self._optimize_is(is_start_ms, is_end_ms)
+            total_trials += 1  # approximate
+
+            # OOS test
+            oos_result = self._test_oos(oos_start_ms, oos_end_ms, best_is.params)
+
+            report.windows.append(WFParamWindow(
+                window_idx=w,
+                is_start=is_start_ts, is_end=is_end_ts,
+                oos_start=oos_start_ts, oos_end=oos_end_ts,
+                best_params=best_is.params,
+                is_sharpe=best_is.sharpe,
+                oos_sharpe=oos_result.sharpe,
+                is_return_pct=best_is.return_pct,
+                oos_return_pct=oos_result.return_pct,
+                oos_trades=oos_result.trades,
+                is_trials=min(n_combos, 1),
+            ))
+
+        report.total_trials = total_trials
+        report.elapsed_seconds = time.time() - start_time
+        return report