NO share — Definition | Polymarket Trade
A NO share is a contract that pays $1 if the underlying event resolves NO; it's the complement of the YES share. On Polymarket, traders buy NO shares to profit if they believe the predicted event will not occur.
In depth
A NO share is a digital contract available on prediction markets like Polymarket that represents a bet against a specific outcome. Each NO share is worth exactly $1 if the underlying question or event resolves to "NO"—meaning the predicted event did not happen or the statement is deemed false. If the event instead resolves to YES, the NO share becomes worthless. In essence, owning a NO share is a way to financially express skepticism or bearish conviction about a future outcome.
The concept of YES and NO shares originates from the combinatorial design of prediction markets. This two-sided structure mirrors how real-world events are binary in nature: either something will happen or it won't. Polymarket adopted this model from earlier prediction-market platforms and refined it to make trading accessible to mainstream users. NO shares matter because they allow traders to express negative views—to profit from being right about something not happening—without needing to use short-selling or derivatives. This democratizes trading; you don't need special leverage or institutional tools to bet that a candidate won't win an election or that a product launch will be delayed.
On Polymarket, a trader encounters NO shares as soon as they open a market page. The platform displays both the YES price and the NO price for every question. If you believe the outcome is unlikely, you can click "Sell NO" to reduce exposure or "Buy NO" to take a contrarian position directly from the trading panel. The interface shows your balance in NO shares as a position, and you can close that position at any time by selling it back at the current market price. Polymarket's real-time orderbook shows the bid-ask spread for both YES and NO, allowing traders to execute at competitive prices. Your profit or loss on a NO position depends on the entry price you paid and the exit price, not directly on the final $1 payout (unless you hold to resolution).
A frequent misunderstanding is that NO shares are inherently riskier or more exotic than YES shares. In reality, they are symmetric: a NO share at 0.30 and a YES share at 0.70 represent the same market opinion, just inverted. Some traders mistakenly treat NO shares as a "short" position in the traditional stock sense, expecting them to decline in value if sentiment shifts against their view. In fact, if the market reprices and NO prices rise because NO becomes more likely, your position gains value, just like any long position. Another pitfall is ignoring the summing constraint: on any binary Polymarket, YES price plus NO price should equal approximately 1.00 minus trading fees. If they diverge significantly, it signals an arbitrage opportunity. Finally, new traders sometimes fail to appreciate that holding NO shares carries real opportunity cost; if the market moves sharply toward YES, your capital locked in NO shares loses purchasing power relative to the YES-side alternative.
NO shares are inseparable from YES shares; the two form a complete market. Every share that resolves has a matching counterparty: your gain on a YES position is someone else's loss on a NO position, and vice versa. The price of a NO share is often used to infer market-implied probability. If a NO share trades at 0.25, the market is implicitly saying there's a 25% chance the event will NOT happen (and 75% for YES). Traders also use NO positions in hedging strategies: if you're long a YES position but want to reduce risk, you can buy NO shares to partially offset your exposure. Polymarket's smart orders—Take Profit, Stop Loss, and Conditional Orders—all work seamlessly with NO shares, allowing traders to automate their exits without constant monitoring. Understanding NO shares is essential to mastering prediction-market dynamics and risk management.
Example
Suppose Polymarket has a market asking 'Will the Federal Reserve cut interest rates in Q3 2026?' with YES trading at 0.65 and NO at 0.35. A trader who believes rates will not be cut might buy 100 NO shares at 0.35 each ($35 investment). If the Fed holds steady and the market resolves NO, those 100 shares pay out $100, netting $65 profit.