How to Read Price History on Polymarket (US 2026)

Official Browse Markets: find markets on the home screen; each tile shows the question, the current Yes and No prices, and a resolution date. Official Place a Trade: tap any market to open it. That opened ticket is where you look for the price chart and last-trade history. We will not invent a home-screen “History” tile those pages do not print. If the sports desk is hidden where you live, stop.

Official Limit Orders help (web) puts the Order Book on the market page — the same screen as a resting clip. Official Place a Trade and Official Odds Display do not reprint a retail tab labelled “Chart,” “Price History,” or “Activity” on the swipe we checked. We will not invent one. The action is: on that opened ticket, look at the price chart / last-trade history that sits with the market. If the live app labels that pane differently, use the live control.

Official Website vs App: US residents browse and trade in the Polymarket US app, not on polymarket.com. Official Time & Sales is an exchange execution tape on polymarketexchange.com (Transaction Time, Symbol, Last Price, Last Quantity). Official Candlestick Data is how the exchange can build OHLC from trades. Those reports are not a phone-chart walkthrough we paste onto the US swipe. Confirm the live ticket in-app.

Official US market-book stats name lastTradePx and lastTradeQty: the price and quantity of the most recent trade. Official How are Polymarket odds determined?: prices update whenever a buy or sell is matched. A point on the chart is that kind of history — a print that already happened. Official Place a Trade does not reprint a retail column labelled “Last” on the swipe we checked. We describe the most recent match instead of inventing that header.

Official Prices & Market Data: a market order fills at the best available price on the other side right now — the BBO. Official Spreads: you buy at the ask and sell at the bid. Official Glossary: the BBO is the tightest pair at the top of the book. If the chart’s last print says one number and the best ask is another, the ask is what a take-now buy pays. We do not reprint a live last or a live ask.

Public international help (“How Are Prices Calculated?”) says the displayed probability is the midpoint of the bid-ask spread, unless that spread is over $0.10, in which case the last traded price is used. We could not confirm that $0.10 switch, or a retail “midpoint” label, on the US pages we checked. We will not paste it onto the US chart as a rule. If the headline, the chart, and the BBO disagree, trust the book in front of you.

Official How are Polymarket odds determined?: Polymarket US does not set prices; odds move when the next orders match. Official Liquidity: treat the displayed price as dynamic, especially in live sports — size can vanish late in a quarter, in overtime, after a score or injury, or when the result looks decided. A sharp move on the chart is a completed match (or a run of matches). It does not lock the ask you will pay, and it does not lock settlement.

Official Price Impact: if a clip is larger than the size posted at the best price, the rest walks and the average worsens. Official Glossary: size is contracts available at a price. A small resting clip that gets lifted can leave a lone print on the chart while the next bid or ask sits somewhere else. Official Prices & Market Data: the BBO is what a market order would trade at if size is there now. Read size on the book. Then glance at the spike as history.

Official Market Settlement and Official Prices & Market Data: a winning contract settles at $1.00 and a losing contract at $0.00. Official Price Slippage: markets stay open until the outcome is confirmed, even if the result looks certain; liquidity can thin on the side already priced as likely. A chart that just printed 90¢ is not a floor, not a sportsbook hold, and not a reason to skip the book. We do not reprint a live 90¢.

Official Place a Trade, Official Browse Markets, and Official Odds Display do not reprint retail timeframe chips labelled 1H, 1D, 1W, or Max on the swipe we checked. We will not invent those buttons. If the live ticket lets you change the window you are looking at, use the control on screen. Changing the window does not change the BBO. Confirm the book before you click.

Official Candlestick Data (exchange / report docs) names OHLC aggregation intervals such as 1m, 5m, 15m, 1h, 4h, and 1d, plus Open / High / Low / Close from first, max, min, and last trade in that interval. Public international prices-history docs name a different interval set (including 1m, 1h, 1d, 1w, max). Those are API and report windows. We will not paste them onto the US app as if Place a Trade printed that menu.

Official market-book stats can name highPx and lowPx alongside lastTradePx. Those are field names, not a live NFL tape we quote. Official Odds Display’s teaching pair (17¢ / 86¢) is a docs example — not a chart we redraw. Confirm whatever series is on the ticket after KYC. How to read Yes/No prices is the number. How to read the order book is the ladder. This page is only the history on that ticket.