Deep audit fixes: A-S gamma scaling + Mean Rev window

1. A-S reservation price now uses gamma*500000 scaling.
   Before: bash.003 skew on 4K BTC (invisible, same as naive dual-quote)
   After:  ~0 skew at max inventory (0.05% of mid — enough to suppress one side)

2. Mean Reversion: 20-tick → 60-tick window, threshold 1.0σ → 0.5σ.
   20 seconds of 1s ticks is noise, not mean-reverting.
   60 seconds captures real short-term reversion dynamics.

Fill attribution verified: BTC sizes differ by 50 μBTC, ETH by 0.0025 — all above matching tolerance.
Orderbook null guards present — no crash on failed fetch.
This commit is contained in:
ramseshk
2026-08-06 08:34:37 +00:00
parent a6905f2691
commit 2429394cd8
2 changed files with 29 additions and 34 deletions
+5 -5
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@@ -184,15 +184,15 @@ def compute_signals():
elif eth_cur < sma-1.2*std: STRATEGIES["Momentum Breakout"]["signals"].append({"time":time.time(),"signal":"SELL","strength":(sma-1.2*std-eth_cur)/std}) elif eth_cur < sma-1.2*std: STRATEGIES["Momentum Breakout"]["signals"].append({"time":time.time(),"signal":"SELL","strength":(sma-1.2*std-eth_cur)/std})
# Mean Reversion: VWAP on ETH (exclude current price from VWAP) # Mean Reversion: VWAP on ETH (exclude current price from VWAP)
if len(eth_prices)>=20: if len(eth_prices)>=60:
w = list(eth_prices)[-20:]; eth_mr = eth_prices[-1] w = list(eth_prices)[-60:]; eth_mr = eth_prices[-1]
# VWAP on prior 19 prices, equal volume weights # SMA deviation on prior 59 prices (60s window captures real mean reversion)
prior = w[:-1] prior = w[:-1]
sma = sum(prior)/len(prior) sma = sum(prior)/len(prior)
vstd = math.sqrt(sum((p-sma)**2 for p in prior)/len(prior)) vstd = math.sqrt(sum((p-sma)**2 for p in prior)/len(prior))
dev = (eth_mr-sma)/vstd if vstd>0 else 0 dev = (eth_mr-sma)/vstd if vstd>0 else 0
if dev>1.0: STRATEGIES["Mean Reversion"]["signals"].append({"time":time.time(),"signal":"SELL","strength":dev}) if dev>0.5: STRATEGIES["Mean Reversion"]["signals"].append({"time":time.time(),"signal":"SELL","strength":dev})
elif dev<-1.0: STRATEGIES["Mean Reversion"]["signals"].append({"time":time.time(),"signal":"BUY","strength":abs(dev)}) elif dev<-0.5: STRATEGIES["Mean Reversion"]["signals"].append({"time":time.time(),"signal":"BUY","strength":abs(dev)})
# Hurst/VPIN: feed BTC price into dollar bars # Hurst/VPIN: feed BTC price into dollar bars
if len(btc_prices)>=3: if len(btc_prices)>=3:
+24 -29
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@@ -10,15 +10,13 @@ Key insight (missed by most naive implementations):
When you're short → reservation price rises above mid → stop quoting ask When you're short → reservation price rises above mid → stop quoting ask
When flat → quote both sides symmetrically at market best bid/ask When flat → quote both sides symmetrically at market best bid/ask
The AS math you paid attention to: Current adaptation for $100/strategy scale:
r = s - q * gamma * sigma^2 * tau - gamma_eff = gamma * 500,000 (~$30 skew at max inventory)
- sigma floor = 0.001 (0.1% minimal vol)
Your inventory-adjusted fair value. Compare to market prices. - Sigma squared floor = 0.000001
- If r < best_bid: you're overpriced on the buy side → don't bid - Skew: r = mid - q_notional * gamma_eff * sigma^2 * tau
- If r > best_ask: you're underpriced on the sell side → don't ask - At max position (0.000950 BTC, $60): skew ≈ $30 = 0.05% of mid
- Enough to visibly suppress one quoting side
This is what Citadel, Jane Street, and every serious MM does.
Quote at market, pick sides based on inventory.
""" """
import math import math
@@ -30,7 +28,7 @@ class ASMarketMaker:
def __init__( def __init__(
self, self,
gamma: float = 0.1, # Risk aversion gamma: float = 0.1, # Risk aversion (scaled internally by 500K)
tau: float = 1.0, # Session length (hours) tau: float = 1.0, # Session length (hours)
max_inventory: float = 0.003, # Max position (3x trade size for BTC) max_inventory: float = 0.003, # Max position (3x trade size for BTC)
vol_window: int = 300, vol_window: int = 300,
@@ -40,6 +38,7 @@ class ASMarketMaker:
self.tau = tau self.tau = tau
self.max_inventory = max_inventory self.max_inventory = max_inventory
self.cb_mult = cb_mult self.cb_mult = cb_mult
self._gamma_scale = 500000 # Aggressive for $100 allocation visibility
self._prices: deque[float] = deque(maxlen=vol_window) self._prices: deque[float] = deque(maxlen=vol_window)
self._sigma: float = 0.01 # fallback: 1% return vol self._sigma: float = 0.01 # fallback: 1% return vol
@@ -73,36 +72,32 @@ class ASMarketMaker:
""" """
Determine which sides to quote. Determine which sides to quote.
Returns: Primary: hard inventory bounds stop quoting over-exposed side.
{"quote_bid": bool, "quote_ask": bool} Secondary: reservation price skew (with 500K gamma scaling for visibility at our size).
Logic: compute reservation price. If it's below best_bid (you're long-biased),
stop quoting bid. If it's above best_ask (you're short-biased), stop quoting ask.
""" """
self.observe(mid) self.observe(mid)
# Hard inventory bounds — never exceed max position # Hard inventory bounds — stop quoting the over-exposed side
if abs(inventory) >= self.max_inventory: if abs(inventory) >= self.max_inventory:
if inventory > 0: if inventory > 0:
return {"quote_bid": False, "quote_ask": True} # Only sell return {"quote_bid": False, "quote_ask": True, "reservation": mid, "sigma": self._sigma}
else: else:
return {"quote_bid": True, "quote_ask": False} # Only buy return {"quote_bid": True, "quote_ask": False, "reservation": mid, "sigma": self._sigma}
# Circuit breaker — pause both sides # Circuit breaker
if self.circuit_breaker(): if self.circuit_breaker():
return {"quote_bid": False, "quote_ask": False} return {"quote_bid": False, "quote_ask": False, "reservation": mid, "sigma": self._sigma}
# Reservation price (return terms → convert to price) # Reservation price with aggressive gamma scaling
tau_rem = max(self.tau - t, 0.01)
# Use notional inventory for meaningful skew
q_notional = inventory * mid q_notional = inventory * mid
# Scale gamma for crypto: multiply by mid for effective skew gamma_eff = self.gamma * self._gamma_scale
gamma_eff = self.gamma * 500 # tuned for ~$100 allocation scale tau_rem = max(self.tau - t, 0.01)
reservation = mid - q_notional * gamma_eff * (self._sigma ** 2) * tau_rem sigma_sq = max(self._sigma ** 2, 0.000001) # floor: 0.1% vol squared
reservation = mid - q_notional * gamma_eff * sigma_sq * tau_rem
# Side selection: only quote when reservation agrees # At $60 notional: skew ≈ $30 → 0.05% of mid — small but directional
quote_bid = reservation >= best_bid # We value the asset enough to buy quote_bid = reservation >= best_bid or abs(inventory) < self.max_inventory * 0.1
quote_ask = reservation <= best_ask # We'd sell at or above our fair value quote_ask = reservation <= best_ask or abs(inventory) < self.max_inventory * 0.1
return { return {
"quote_bid": quote_bid, "quote_bid": quote_bid,