How My Polymarket Dual-Leg Arbitrage Bot (@dual-leg) Generated +$2,506 in 24 Hours — Full Strategy Breakdown

#polymarket #tradingbot #traders

[Intro paragraph]

In May 2026 I launched @dual-leg on Polymarket. In just weeks it has racked up 222 predictions and delivered +$2,506.86 in realized profit in the last 24 hours alone. Positions are currently at $0.00 — everything is closed and banked.

This isn’t a directional prediction bot. It’s a pure dual-leg arbitrage engine that exploits tiny, mathematically guaranteed inefficiencies in Polymarket’s binary Up/Down markets.

The Math Behind Dual-Leg Arbitrage

Every Polymarket binary contract (e.g. “Bitcoin 15-Minute Up or Down”) has two outcomes:

YES (Up) share
NO (Down) share

At resolution the correct share always pays exactly $1.00. Therefore:

Up price + Down price must equal $1.00 at settlement.

When the sum of the best available ask prices dips below $1.00, you can buy one share of each and lock in risk-free profit:

Example:

Best ask Up = $0.48
Best ask Down = $0.49 → Total cost = $0.97 → Guaranteed payout = $1.00 → 3.09% locked profit (minus tiny fees/slippage)

The edge is small per trade, but the frequency is massive.

How the Bot Works (Technical Deep Dive)

Market Scanner

Continuously monitors every active short-term crypto binary market via Polymarket’s public API and WebSocket order books.
Mispricing Detector

Real-time calculation:

if (best_ask_Up + best_ask_Down) < THRESHOLD (e.g. 0.985) → trigger.
Atomic Dual-Leg Execution

The critical part. The bot places both buy orders in the same micro-batch with strict timing (≤50 ms window).
- If one leg fails → auto-cancel or hedge the other instantly.
- Retry logic on transient failures.
- Liquidity & volume filters prevent getting stuck in thin markets.
Position Management
- Hold to resolution for full edge, OR
- Exit early when prices converge (faster capital turnover).
- Dynamic position sizing based on available edge and current portfolio risk.
Risk Controls
- Never naked (always both legs).
- Max exposure per market.
- Automatic shutdown on extreme volatility or API issues.

Result? Near-zero directional risk and compounding small edges 24/7.

Real Performance (as of May 6, 2026)

Account: @dual-leg (joined May 2026)
Predictions: 222
24-hour realized PNL: +$2,506.86
Current positions value: $0.00 (fully realized)
Track record: https://polymarket.com/@dual-leg

This is the same class of strategy that has been documented turning tiny starting capital into six figures in weeks — but @dual-leg is battle-tested and running live right now.

Why I’m Selling the Account

The bot has proven the strategy works at scale. I’m now liquidating the full account + complete automation setup to free up capital for the next phase of development.

Serious buyers only — full handover, documentation, and live monitoring included.