Prediction market questions, answered

Traders buy and sell shares in binary outcomes, Yes or No. Each share pays $1 if the outcome happens and $0 if it does not. A price between $0 and $1 is the implied probability. Buy a Yes share at $0.60 and you receive $1 if the event happens, a $0.40 profit. If it does not happen, you lose the $0.60.

Prediction markets have beaten polls, expert panels, and statistical models on many forecasts, especially binary political outcomes and economic events. The accuracy comes from the money at stake: a trader with better information profits by correcting the price, which pushes it toward the true probability.

Both involve risk. A prediction market also does price discovery: it aggregates information into probability estimates with real forecasting value. You can trade in and out continuously, run strategies beyond a single bet, and the price comes from peer-to-peer supply and demand rather than a house-set line.

A binary market is a prediction market that resolves to one of two outcomes, Yes or No. The price of a Yes share is the implied probability of the event happening. Binary markets are the most common format on Polymarket.

Four ways: (1) Buy underpriced shares and hold to resolution. (2) Trade the price move before resolution, as new information shifts the probability. (3) Market make by posting liquidity and collecting the bid-ask spread. (4) Arbitrage price differences between related markets or platforms.

The common approaches are market making, accumulation, event-driven trading, directional trading, and swing trading. 0xinsider sorts wallets into 10 strategy types with a fixed set of rules applied to their trading patterns, so you can see whether a trader provides liquidity, builds positions slowly, or trades around events. The label says how a wallet trades, not whether that strategy wins.

Look past the headline P&L. Profit factor, Sharpe ratio, equity smoothness, max drawdown, and concentration across markets tell you how a trader makes money as well as how much. 0xinsider computes each of these per wallet. A number the history cannot support stays hidden: win rate needs 5 markets traded, and the Sortino percentile needs 50 resolved markets.

The Kelly criterion is a formula for position sizing: f* = (bp - q) / b, where b is the decimal odds minus one, p is your estimated probability, and q = 1 - p. It sets what fraction of your bankroll to risk, given your edge. Most traders use fractional Kelly, which cuts the swings and keeps expected growth positive.

Warning signs include large trades placed shortly before market-moving events, unusual patterns from previously inactive wallets, coordinated buying across multiple wallets, and a large gap between entry price and eventual resolution. None of these proves informed trading on its own; each is a reason to look closer.

They serve different purposes. A prediction market has no house edge: traders set the price against each other, though some markets charge a taker fee. A prediction market also covers a wider range of events and lets you make markets or sell before resolution. A sportsbook has simpler apps, established regulation, and deeper liquidity in some categories. A trader working from analysis gets more room on a prediction market.

0xinsider builds Polymarket analytics & infrastructure for sports and esports markets. Large Polymarket trades land in one feed, linked to the wallet behind each one, with grades and analytics built from each wallet's own history across 184K+ tracked wallets. The feed is live on Pro and runs 24 hours behind without it. Scores and flags tell you where to look. They do not predict outcomes.

0xinsider grades each wallet from S to F, led by realized profit: the wallet's net realized P&L on Polymarket, fees included and rebates credited, with open positions left out. Realized profit is about 95% of the grade. The other 5% is a tie-breaker built from forecasting edge, track record, drawdown, equity smoothness, win rate (held to a Wilson lower bound), and the Sortino ratio, and it only separates wallets whose realized profit is already close. The public board shows only S, A, and B, and guardrails decide who reaches it. Any grade above C needs net-positive realized profit and at least 10 resolved markets. A needs 50 resolved markets and $20K of volume, S needs 200 and $50K, and both need a worst loss of no more than 10% of everything the wallet ever put to work. A wallet idle for 30 days drops to B at most, and after 120 days to C. Proven wallets that clear every gate also get a floor from banked profit: $1M or more lifts one to S, $250K to A, and $100K to B. Open gains never count, so the board shows who has banked the most, not who holds the biggest paper number. 296.5K+ wallets currently have a daily P&L history, which the drawdown and smoothness inputs are built from.

The review score gives each large trade a 0.0 to 1.0 score from four inputs: the trade's size, the wallet's win rate, how recent the trade is, and a bonus when a wallet that wins more than 55% of its resolved markets trades below 30¢. The score is published in the API; no page on the site shows it. It does not measure how much graded money is on a side, predict an outcome, or claim complete exchange coverage.

0xinsider's suspicion score helps prioritize unusual trades for review. A higher score indicates a stronger anomaly flag; it does not establish what a trader knew. The suspicion score is an anomaly ranking that tells you where to look. It is not proof of informed trading, misconduct, or a future outcome.

Yes. Search your Polymarket username or wallet address. A wallet 0xinsider has not seen before is imported from Polymarket when you search it, and its profile fills in as the history loads. Win rate appears once the wallet has traded 5 markets, and a grade once its history is complete enough to score.

0xinsider processes on-chain Polymarket data: trades, position changes, market outcomes, large trades, trader behavior patterns, and the market metadata behind rankings, review scores, and category analytics.