6 min readPrediction markets

What “+EV” means on prediction markets (and what it does not mean)

A clear, non-technical explanation of expected value style thinking on Polymarket-style markets, common pitfalls, and how Predlyx frames +EV as research—not a promise. Not financial advice.

In trading slang, “+EV” usually means “positive expected value” under a model: the idea that repeating similar bets at similar prices would—on average—produce a favorable outcome. On prediction markets, that concept is useful for disciplined thinking and dangerous when treated as a guarantee.

Models can be wrong

Every +EV label depends on assumptions: fair probability, fee treatment, liquidity, and whether the contract resolves the way you think. If the model is wrong, the sign flips. Treat +EV outputs as hypotheses to investigate, not instructions.

How Predlyx uses +EV

Predlyx provides a +EV finder to help you discover rows worth reviewing with fees in mind. It is an analytics tool for people who already understand that markets can move against you and that “edge” is never free.

If you are learning

Start small, read each exchange’s rules, and separate research time from execution time. Consider recording decisions and outcomes so you improve your process over weeks, not minutes.

Predlyx offers a 7-day trial and paid plans if you want the full scanner experience—see pricing for details.

Scan both exchanges in one workspace

Predlyx matches Polymarket and Kalshi, surfaces fee-aware arb and +EV rows, and helps you log P&L. Start your 7-day trial or compare plans.