Arbitrage#001

Yes/No Complement Arbitrage

Every binary market has a Yes share and a No share that should always add up to exactly $1.00, since one of them is guaranteed to be worth $1 at resolution. When the two prices instead add up to more than $1.00, you sell both sides (or short the overpriced pair) and pocket the difference no matter how the event turns out. The profit is locked in the moment you fill both legs; it just takes patience to hold until the market resolves.

What you need to run it

Real-time order book scanner across all binary markets
Enough capital to hold both sides until market resolves
Low-latency execution to capture the spread before it closes

Where this applies

Markets on Polymarket where yes/no complement arbitrage is the natural play:

Will Bitcoin be up at 4pm ET today?
Will the Yankees beat the Red Sox tonight?
Will Ethereum close above $3,500 on July 31, 2026?

Capabilities this demands

Low latencyCustom code / APISignificant capitalMulti-venue

At a glance

CategoryArbitrage

Requirements3

CapabilitiesLow latency, Custom code / API, Significant capital, Multi-venue

VenuePolymarket (CLOB, Polygon)

Build it

Related arbitrage strategies

This is documentation, not advice. Poly Research & Robotics publishes how these strategies work because the method should be checkable — not as a recommendation to trade them. See the full strategy database (147 strategies) or the data resources directory.