When mutually exclusive outcomes on Polymarket sum to less than 100%, buying every leg locks profit at resolution. WhalesInsider scans neg-risk events continuously and ranks arbitrage by edge %.
On prediction markets, price moves in seconds. Free sees the same whale bet — too late.
Free (15 min delay)
Whale buys YES @ 42¢ · you see it @ 54¢
Edge gone — worse fill or missed trade
Premium (instant)
Same alert · you copy @ 43¢
Copy smart money while the book still moves
Not every arbitrage is actionable — you need complete outcome coverage and enough ask liquidity on each leg.
Arbitrage is math-driven; whale bets are flow-driven. Sharp bettors use both: arbitrage for locked ROI, whales for directional edge when you lack a model.
Only if you buy ALL outcomes in a complete set and resolution rules match your assumption. Incomplete sets or rule surprises carry risk.
Positive arbitrage is the highest-value signal — full legs and Polymarket links are gated to Premium subscribers.
More often in fast-moving sports and news catalysts; scanner refreshes from Gamma API continuously.