The Favorite-Longshot Bias: Why 95¢ Contracts Are the Best Trade Nobody Wants

The Bias That's Been Around Longer Than Prediction Markets

Horse bettors figured this out in the 1940s. When you sort every horse race by odds and look at actual win rates, favorites are systematically underbet and longshots are systematically overbet. A 30-to-1 horse wins less than 30-to-1 implies. A 2-to-1 favorite wins more than 2-to-1 implies.

This is the favorite-longshot bias, and it shows up everywhere humans bet on things. Sportsbooks. Options markets. Roulette. And yes — Kalshi and Polymarket.

Why It Happens

People like upside. A $10 bet that pays $500 feels like a story. A $95 bet that pays $5 feels like picking up nickels in front of a steamroller. Both can be +EV, but only one gets posted to Twitter.

There's also a psychological cost to holding a 95¢ YES contract. You're staring at 5% upside and 95% downside. Every tick against you feels catastrophic even when the probability hasn't actually moved. Most traders can't stomach it, so they don't hold it, so it stays mispriced.

And here's the kicker: the people who *would* correct the mispricing — the sharps with real capital — often skip these markets because the return on capital looks unsexy. Tying up $9,500 to make $500 doesn't get you rich fast, even if the edge is real.

What This Looks Like in Practice

Go find a market where the outcome is essentially decided but hasn't resolved yet. An incumbent politician who's polling +15 the week before the election. A championship team up 3-1 in a best-of-seven. A Fed decision two days out where every governor has already signaled.

You'll often see these contracts trading at 93-96¢ when the real probability is closer to 98-99%. That gap is the bias. Not because the market is stupid — because nobody wants to park capital in a boring near-certainty when there's a fresh election market with 40¢ / 60¢ action right next to it.

How to Actually Trade It

Size for the downside, not the upside. If you're buying at 96¢, your loss on a bad outcome is 96¢ per contract. Don't think of it as "only 4¢ at risk" — think of it as "I'm risking almost my entire position for a small payout." One bad resolution wipes out 20+ winners.

Diversify across uncorrelated favorites. One 96¢ contract is a coin flip on getting embarrassed. Ten 96¢ contracts across independent events is a portfolio. The math only works when the losses are spread out.

Watch for real tail risk. The bias exists because the market slightly *overweights* longshots. But sometimes the longshot is right. A 95¢ contract on a Supreme Court ruling before oral arguments? That's not a favorite — that's a market pricing genuine uncertainty. Learn the difference between priced-in certainty and assumed certainty.

Mind the fees and time value. A 4¢ edge gets eaten fast by spreads, gas fees, and the opportunity cost of locked capital. If the market resolves in six months, your annualized return on that 96¢ contract might be worse than a T-bill.

The Meta Point

The favorite-longshot bias is boring. That's why it works. Every edge that survives in a market survives because it's psychologically unpleasant to exploit — otherwise it would be arbed out.

If you find yourself thinking "this trade is fine but I don't really want to make it," pay attention. That feeling is the edge. The trades that feel exciting are usually the ones where you're the exit liquidity for someone smarter.

Boring wins. Slowly. On purpose.