How Polymarket works: shares, prices, resolution, fees

Shares that pay $1 or $0

Every market has outcome shares, usually Yes/No or Up/Down. A share of the outcome that happens pays exactly $1 at resolution; the other pays $0. Before resolution shares trade between $0.01 and $0.99 on an order book, like a stock. A price of 0.63 means the crowd currently assigns about 63% to that outcome.

Buying, selling, holding

You can hold to resolution or sell earlier at the current bid. Buying Yes at 0.63 and selling at 0.80 locks in 0.17 per share without waiting for the event. Buying No is the mirror: No at 0.37 is the same bet as not-Yes.

Resolution

Each market states its resolution source in the description. Read it: "by October 31" may mean 11:59 PM ET, sports resolve on official results, crypto Up/Down markets resolve on a 60-second time-weighted Chainlink price, not on a single print. Disputes go through UMA and can delay payouts by days.

Fees

Many event markets have no trading fees. Sports and crypto markets charge a taker fee that peaks around 50/50 prices (about 3.5% of notional at 0.50) and vanishes near 0.01 or 0.99. Makers who post resting orders pay nothing and can receive rebates. Deposits and withdrawals in USDC on Polygon cost cents.

What moves prices

News, order flow and liquidity. Thin markets move several cents on a $500 order; big political markets absorb $50k. Check the depth before you size a position.