How to Read Average Entry on Polymarket (US 2026)

Official Monitor Your Positions lists average entry price on the open position, next to contracts held, current market price, and potential payout. Official Glossary: an open position is the contracts you currently hold; a fill is when an order completes; execution price is the price of that fill. Average entry is your cost on the shares still sitting in Portfolio — not the headline Yes/No on the ticket, and not a number we reprint.

Official Positions & Risk (trader / API docs) names Cost Basis as average entry price, total cost, and the input to unrealized P&L. That is the concept this page is reading. Official Monitor Your Positions, Official Place a Trade, and Official Glossary do not reprint a retail column literally labelled “Cost Basis.” We will not invent one. If the live Portfolio prints that phrase, use the live label. If it only prints average entry, that is the published US field.

Official Glossary: fill price is the average price you receive when your order fills across multiple levels. Official Prices & Market Data: a marketable buy pays the best available price on the other side if size is there. A single swipe that walks the book is already a blend. That blend is still your entry, not the last print someone else made on the same ticket.

Official Place a Trade: after you swipe, open the Portfolio tab to track the position and market value. Official Website vs App: US residents deposit and trade in the Polymarket US app, not on polymarket.com. Official Monitor Your Positions is the filled ticket. If the live app labels the same screen Profile, Positions, or something else, use the live control — we will not invent a second header those pages do not print.

Official Monitor Your Positions: the portfolio shows cash balance, open positions, and total account value. On each open position you can also see contracts held, average entry price, current market price, and potential payout. Those are the published names. We do not reprint a live dollar on any of them.

Official US market-book stats name lastTradePx as the most recent match on that market — anyone’s print. Official Place a Trade does not reprint a retail column labelled “Avg,” “Avg | Cur.,” or “Cost Basis” on the swipe we checked. Legacy international help once printed Avg | Cur. We will not paste that header onto the US app. Find average entry on the open-position row Official Monitor Your Positions already names. If the live screen shortens the label, use the live text.

Official Glossary: a fill completes an order, fully or in part; execution price is what that fill paid. Official Orders & Trading: once an order fills, you have a position; a later order can add to the contracts you hold. Two completed buys of the same Yes (or the same No) at two different execution prices are not the same print. The published average entry on that open position is the blend of what you paid for the contracts still there — not whichever clip printed last.

Official Glossary: fill price averages across the levels one order actually hit. Official Spreads: you buy at the ask. If the first clip at the best ask is smaller than your size, the rest of that same order can pay a worse ask. That is one swipe, two (or more) execution prices, and one fill-price average. It is still not the market’s lastTradePx.

Official US Monitor Your Positions names the field. Official Positions & Risk names cost basis as average entry and total cost. Neither page prints a retail weighted-average equation, a teaching table of two ticket sizes, or a promise that fees sit inside or outside that average. Official Glossary separately names fees as a charge on executed orders. We will not invent the net. Confirm the live average entry after the second fill. Teaching cents on this page are not tonight’s book.

Official US market-book stats name lastTradePx (and lastTradeQty): the price and quantity of the most recent trade on that market. Official How are Polymarket odds determined?: prices update whenever a buy or sell is matched. That tape is history for the whole book. It is not your average entry unless your fill happened to be that last match — and even then, a later print by someone else will move lastTradePx while your average stays put.

Official Monitor Your Positions sits current market price next to average entry. Official Place a Trade: positions update in real time as prices change. Official Prices & Market Data: a take-now order pays the BBO if size is there. Official Spreads: you buy at the ask and sell at the bid. The mark can sit above or below your average without either number being last trade.

A teaching last match at 40¢ is the last time any two orders crossed. Your average entry is the blend of your fills. You can hold a position whose average is away from that 40¢ print, and you can have no position at all while the tape still shows 40¢. We do not reprint a live last or a live average. How to read Yes/No prices is the tile. This page is only your cost on the row you hold.

Official Monitor Your Positions: current market sits next to average entry; total value is cash plus positions. Official Glossary: position value is the real-time dollar value of open positions. Official pages we checked do not print a retail column header literally labelled “P&L.” Official Positions & Risk says unrealized P&L is mark versus cost basis — that is trader-guide language, not a US retail tab we will invent. The action you are reading is the gap. It is not a debit-card credit.

Official Check Your Balance and Official Glossary: cash is the money not tied to any open position. Official Monitor Your Positions: cash is funds available to trade or withdraw. Official Check Your Balance: proceeds from sales or resolved markets return to cash automatically. Withdrawals come only from that cash — and only after the funding deposit has fully cleared. Average entry does not become withdrawable by sitting on the row.

Official “Why does my position look down right after I buy?”: Polymarket US only fills whole contracts. Leftover dollars from a dollar-amount order return to cash, so Portfolio can show the position slightly down even though you did not take a market loss. That FAQ is not a live P&L we reprint, and it is not the same fact as a second fill rewriting average entry. Do not treat the leftover-dollars mark as realized cash gone.