feat: cancel cheap side on expensive fill + auto-redeem after resolution

- MAKER_MM_CANCEL_CHEAP_ON_EXP_FILL=true: when the expensive side fills
  first, immediately cancel the cheap side order and hold the token.
  After market ends, polls on-chain payoutDenominator until resolved,
  then calls redeemPositions to recover USDC.
- Default false — existing symmetric maker behavior unchanged.
- Redeem polls every 15s for up to 10 minutes after market close.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -102,6 +102,11 @@ MAKER_MM_REENTRY_ENABLED=true
 MAKER_MM_MIN_PRICE=0.30
 MAKER_MM_MAX_PRICE=0.69
 
+# Cancel cheap side when expensive side fills first, then hold and auto-redeem at resolution
+# Example: YES=5c, NO=94c → NO fills first → cancel YES, hold NO, redeem after market ends
+# Default false (symmetric maker behavior — wait for both sides)
+MAKER_MM_CANCEL_CHEAP_ON_EXP_FILL=false
+
 # ── Current Market Entry (optional) ─────────────────────────────
 # Allow entering markets that are already in progress
 # Useful for catching mid-market opportunities

src/config/index.js

@@ -100,6 +100,8 @@ const config = {
   makerMmRepriceThreshold: parseFloat(process.env.MAKER_MM_REPRICE_THRESHOLD || '0.02'), // reprice if bid drifts > this (default 2c)
   makerMmMinPrice: parseFloat(process.env.MAKER_MM_MIN_PRICE || '0.30'),   // min bid for rebate range (both sides)
   makerMmMaxPrice: parseFloat(process.env.MAKER_MM_MAX_PRICE || '0.69'),   // max bid for rebate range (both sides)
+  // When true: if expensive side fills first, cancel cheap side and hold to redemption
+  makerMmCancelCheapOnExpFill: process.env.MAKER_MM_CANCEL_CHEAP_ON_EXP_FILL === 'true',
 
   // ── Current Market Settings ────────────────────────────────────
   // Enable trading on current active market (not just next market)

src/services/makerRebateExecutor.js

@@ -12,7 +12,7 @@ import { Side, OrderType } from '@polymarket/clob-client';
 import { ethers } from 'ethers';
 import config from '../config/index.js';
 import { getClient, getUsdcBalance, getPolygonProvider } from './client.js';
-import { mergePositions } from './ctf.js';
+import { mergePositions, redeemPositions } from './ctf.js';
 import { mmFillWatcher } from './mmWsFillWatcher.js';
 import logger from '../utils/logger.js';
 
@@ -351,6 +351,24 @@ async function monitorUntilFilled(pos, tag, label) {
                 logger.money(`MakerMM${tag}: NO filled (onchain) ${noShares.toFixed(4)} shares`);
             }
 
+            // ── Cancel cheap side when expensive fills first ──────────────────────
+            // When enabled: if the expensive side fills and cheap side hasn't,
+            // cancel the cheap order and hold the expensive token to redeem at resolution.
+            if (config.makerMmCancelCheapOnExpFill) {
+                const expSide  = pos.yes.buyPrice >= pos.no.buyPrice ? 'yes' : 'no';
+                const cheapSide = expSide === 'yes' ? 'no' : 'yes';
+                if (pos[expSide].filled && !pos[cheapSide].filled) {
+                    logger.info(
+                        `MakerMM${tag}: ${expSide.toUpperCase()} ($${pos[expSide].buyPrice}) filled first — ` +
+                        `cancelling cheap ${cheapSide.toUpperCase()} ($${pos[cheapSide].buyPrice}) order`
+                    );
+                    await cancelOrder(pos[cheapSide].orderId);
+                    pos.holdingSide = expSide;
+                    pos.status = 'holding';
+                    return;
+                }
+            }
+
             // ── Over-position safety net ────────────────────────────────────────
             // If one side's balance is > 1.5x target AND the current order is still open,
             // a double-fill occurred (old cancelled order + new order both filled).
@@ -569,6 +587,51 @@ async function executeMerge(pos, shares, tag) {
     }
 }
 
+// ── Auto-redeem after market resolution ──────────────────────────────────────
+// Used when holding a single-sided position (expensive side filled, cheap cancelled).
+// Polls until the market resolves on-chain, then calls redeemPositions.
+
+async function waitAndRedeem(pos, tag) {
+    const endMs = new Date(pos.endTime).getTime();
+    const waitForEndMs = endMs - Date.now();
+
+    if (waitForEndMs > 0) {
+        logger.info(`MakerMM${tag}: holding ${pos.holdingSide.toUpperCase()} — waiting ${Math.round(waitForEndMs / 1000)}s for market to end...`);
+        await sleep(waitForEndMs);
+    }
+
+    if (config.dryRun) {
+        logger.info(`MakerMM${tag}: [SIM] would redeem ${pos.holdingSide.toUpperCase()} after resolution`);
+        return;
+    }
+
+    logger.info(`MakerMM${tag}: market ended — polling for on-chain resolution...`);
+    const provider = getPolygonProvider();
+    const ctf = new ethers.Contract(CTF_ADDRESS, ['function payoutDenominator(bytes32 conditionId) view returns (uint256)'], provider);
+    const maxWaitMs = 10 * 60 * 1000; // 10 minutes max
+    const pollMs = 15_000;
+    const start = Date.now();
+
+    while (Date.now() - start < maxWaitMs) {
+        try {
+            const denom = await ctf.payoutDenominator(pos.conditionId);
+            if (!denom.isZero()) {
+                logger.info(`MakerMM${tag}: market resolved — redeeming ${pos.holdingSide.toUpperCase()} tokens...`);
+                await redeemPositions(pos.conditionId, pos.negRisk);
+                logger.money(`MakerMM${tag}: redemption complete`);
+                return;
+            }
+        } catch (err) {
+            logger.warn(`MakerMM${tag}: resolution poll error — ${err.message}`);
+        }
+        const elapsedSec = Math.round((Date.now() - start) / 1000);
+        logger.info(`MakerMM${tag}: not resolved yet (${elapsedSec}s / ${maxWaitMs / 1000}s) — retrying in ${pollMs / 1000}s...`);
+        await sleep(pollMs);
+    }
+
+    logger.warn(`MakerMM${tag}: market not resolved after ${maxWaitMs / 60000} minutes — skipping auto-redeem (tokens remain in wallet)`);
+}
+
 // ── Main entry ───────────────────────────────────────────────────────────────
 
 export async function executeMakerRebateStrategy(market) {
@@ -839,6 +902,12 @@ export async function executeMakerRebateStrategy(market) {
     await monitorUntilFilled(pos, tag, label);
     activePositions.delete(conditionId);
 
+    // If holding a single-sided position (expensive filled, cheap cancelled) — wait and redeem
+    if (pos.holdingSide) {
+        await waitAndRedeem(pos, tag);
+        return { oneSided: false }; // not a stuck one-sided cycle, intentional hold
+    }
+
     const sign = pos.totalProfit >= 0 ? '+' : '';
     logger.info(`MakerMM${tag}: done | P&L: ${sign}$${pos.totalProfit.toFixed(2)}`);