How to trade prediction markets during elections

Elections drive more prediction market volume than anything else. The 2024 US presidential election alone generated over $3 billion in trading volume on Polymarket. Elections have what a market needs: high public interest, abundant public information, clearly defined outcomes, fixed resolution dates, and uncertainty that lasts until the result.

The volume makes trading cheap. Spreads tighten to 1¢ or less in major markets, and the crowd is large enough that diverse views reach the price.

Efficient does not mean accurate. Election markets misprice outcomes early in a race, in down-ballot contests, and when information changes fast. The competition is strong, so the traders who profit prepare months ahead and have a plan for each stage.

The widest mispricings come months before primary voting begins. Markets price early polls, pundit takes and general sentiment. Many traders are not watching yet and liquidity is thin, so early research pays most here.

One approach is to find outcomes the market underprices on structural factors: strong fundraising, institutional support, or demographic advantages that early polls have not picked up. Markets overweight recent headlines in this phase. A candidate who raised $50 million in Q3 and polls at 8% may be badly underpriced if that money is about to become advertising and organization.

Another is to trade the link between a candidate's primary and general election markets. Say the primary sits at 60¢ and the general at 30¢, so the market gives the candidate an even chance in the general once nominated. If you put the primary at 80%, the same even chance prices the general at 40¢ against the 30¢ listed, and the general may offer better risk-adjusted value than the primary itself. The chart at the top of this guide draws that arithmetic.

Primary season moves fastest: debates, polls, endorsements and early-state votes all reprice markets. Not every poll is equally informative. A high-quality poll of likely voters in the next primary state beats a national poll of registered voters taken months before voting begins.

State-by-state primary markets offer some of the best opportunities. They are less liquid than national markets and more sensitive to local information. A trader who follows New Hampshire politics closely has a real edge in the New Hampshire primary market over people running national-level analysis. The same goes for Super Tuesday states, delegate-rich states, and states with unusual primary rules.

Momentum matters most in primaries. When a candidate beats expectations in an early state, the markets for the next states often do not fully adjust, and a candidate who underperforms may stay overpriced in later markets. The window after a primary result is measured in hours, not days.

A poll is a survey of voter intent at one moment. A market price is a live aggregation of trader beliefs backed by money. They diverge often. When they disagree, one of them is wrong, and working out which is a tradeable edge.

Polls are most reliable when they are recent, use likely-voter screens and large samples from proven pollsters, and agree across firms. When 3 A-rated pollsters show the same candidate ahead by 5 points, the signal is strong. If the market prices a tighter race, traders may be weighing something the polls miss, or the market may be wrong. Your job is to decide which.

The repeatable edge is speed on new polls. When a high-quality poll is released and the market has not absorbed it, watch the release, judge its quality, and trade before the price adjusts. Polling aggregators and tracker sites surface new data as it lands.

Election night is the most volatile period in prediction market trading. Prices swing by tens of percentage points as votes are counted and results arrive state by state.

The edge is knowing the order of the count. In many US states, mail-in votes, which lean toward one party, and in-person votes, which lean toward the other, are counted in different sequences, so early results can look nothing like the final count. A trader who knows a state counts mail-in ballots first stays calm when the early numbers favor one candidate. The market, full of participants who do not know these mechanics, overreacts.

Size smaller than usual. Volatility is extreme and liquidity is unpredictable. Cut position sizes by half on election night and focus on a few states or races where you understand the counting process best.

In a close race the gap between election day and official resolution can run days or weeks. Markets stay open and prices converge on the result as counting continues, which rewards traders who can assess the remaining vote.

The arithmetic is simple. A candidate leads by 10,000 votes with 100,000 mail-in ballots left. If those ballots break 60-40 for the trailing candidate, the trailer gains 20,000 and wins by 10,000. At a 55-45 break the race is a dead heat. The chart above shows the final margin at each split. Traders who run that calculation fast profit from the slow adjustment of prices.

Read the resolution criteria before trading. Some markets resolve on the certified result, others on the projected winner, others on media calls. In a contested election, legal challenges delay resolution even when the count looks decisive, and the payout depends on the oracle's reading of those criteria.

After the election resolves, review your trades and your calibration. An election season is the largest sample of correlated political markets you will see. Compare your results with the top-ranked political traders on 0xinsider.

The 2024 US presidential election was the largest prediction market event in history, and 4 patterns from it are worth keeping.

Markets can be wrong for long stretches. Prices diverged sharply from polling aggregates at several points in the campaign. Resolution validated the market over the polls in some contests and the polls over the market in others.

Liquidity was concentrated. The presidential race drew billions in volume at extremely tight spreads, while down-ballot races had orders of magnitude less liquidity and much wider spreads. Senate, gubernatorial and proposition markets carried recurring mispricings that the presidential market did not, and specialists could beat them.

Election night followed the counting order. Traders who knew which states count early votes first, which count in-person first, and which have same-day registration held large information advantages during the count. These patterns are structural and will repeat.

Prices fed back into the race. Prediction market prices influenced public discourse, media coverage and campaign strategy. A leading candidate whose price drops can face negative coverage that damages their prospects further, which is both a risk and an opportunity for traders who see it coming.