Guide

Prediction market strategies that real traders use

Prediction markets reward a different kind of edge than sportsbooks. Prices are set by other traders, fees follow a formula, and every venue has its own order book. These five strategies come up again and again, along with how each one goes wrong.

1. Cross-market arbitrage

When the same event is priced differently on two venues, buying YES on one and NO on the other can cost less than $1 for a contract that pays $1 either way. The catch: gaps are usually small, both venues charge fees, one leg can fail to fill while the other does, and two venues can settle the same question differently.

What it needs: accounts on more than one venue, speed, and the fees counted on both sides. Near 50¢ the fees on a two-sided trade are about 3.5¢ per pair.

2. Following the whales

Big trades are public on Polymarket and visible on Kalshi's trade tape. A large bet from a trader with a good record can be a useful signal. Most large trades aren't bets at all, though: they're hedges, market making or flips.

Where it goes wrong: copying after the price has already moved, or copying a trade the whale exits an hour later. See the copy trading guide.

3. Fair odds: comparing against the market's consensus

A price is the market's guess at a probability. When several venues price the same outcome, the average with the fees and margin taken out is a decent estimate of the fair chance. A venue pricing an outcome well below that is offering better odds than the consensus.

Where it goes wrong: a consensus can be wrong, and fair odds only pay off over many bets, not on any one.

4. Posting resting orders instead of taking prices

Takers pay the fee; on some venues makers don't. Resting orders are free on Polymarket US and Polymarket, free on Gemini through 2026, and 0.0175 on Kalshi series that charge makers. Posting a limit order and waiting can save most of the fee.

Where it goes wrong: your order may never fill, or fill only when the price is moving against you.

5. Sizing and small-order costs

Venues that round fees up to the cent charge at least 1¢ on any order with a fee. On a 5¢ contract that's 20% of the price. Fewer, larger orders cost less than many small ones. And the size you can trade is limited by what's actually for sale at that price.

The common thread

Every one of these is an edge, not a sure thing. Fees, fills and settlement rules decide whether a good idea actually pays. Count all three before you trade.

Common questions

What is the best prediction market strategy?

There isn't one best strategy. Arbitrage pays the same whoever wins but needs speed and accounts on two venues. Following whales and fair-odds betting are bets on outcomes. All of them depend on fees and fills.

Is prediction market arbitrage risk-free?

No. Gaps close fast, one leg can fail to fill, and two venues can settle a question differently. It reduces risk compared with a one-sided bet, but doesn't remove it.

How do fees affect prediction market strategies?

Most venues charge rate times contracts times price times (1 minus price). Fees are highest at 50 cents and small near the edges, so the same strategy can pay at 90 cents and lose at 50 cents.

Do I need multiple accounts?

For cross-market arbitrage, yes. For the other strategies, one venue works, though comparing prices across venues helps you get a better entry.