What is Polymarket and how does it work?

A plain-English explanation of Polymarket: what a prediction market is, how YES/NO shares are priced, how markets resolve, and what the real risks are.

Polymarket is a prediction market — a place where people trade real money on the outcome of future events, and the price of a share is the market’s estimate of how likely that event is. This guide explains the mechanics in plain language, how the numbers work, and what to watch out for before you put money in.

What a prediction market is

A prediction market works like a stock market, but the "stock" is an event outcome. A market asks a yes-or-no question — "Will candidate X win?", "Will BTC close above $100k this month?" — and traders buy shares in the answer they expect.

Each share pays $1 if the outcome happens and $0 if it does not. A share trading at $0.62 means the market collectively thinks that outcome is 62% likely. The price is the probability, expressed in dollars.

How a market works, step by step

Each market has two sides — YES and NO — whose prices always add up to $1. If YES costs $0.62, NO costs $0.38. You buy the side you expect, or sell the side you already hold to lock in a price.

When the event resolves, the winning side pays $1 per share and the losing side pays $0. If you bought YES at $0.62 and the event happened, you made $0.38 per share. If it did not happen, you lost your $0.62.

Markets are settled against a written resolution source — an official result, a data feed, or a price reading — agreed before trading starts. You do not have to wait until the end: you can sell your shares to someone else at any time at whatever the market is willing to pay.

What makes Polymarket different

Polymarket runs on a public blockchain, so every trade is on-chain and visible. Settlement happens automatically against the resolution source, and positions are funded with USDC, a dollar-pegged stablecoin.

The transparency matters: anyone can look up a market’s trading history, and any trader’s positions are public. That is also the reason copy-trading is possible at all — every trade is a matter of public record.

The honest risks

The most important thing to understand: prices can be wrong, and being right about the world does not mean you make money. You profit only if your estimate is more accurate than the market’s — and the market is the collective estimate of everyone else, including people who may know more than you.

Prediction markets also resolve to zero or one with nothing in between. A position that was briefly worth $0.90 can pay $0. There is no partial consolation. Position size is the only real protection.

How most people participate

There are broadly three ways to use Polymarket. The first is to trade your own view — research an event, form an opinion, take a position. The second is to trade the flow — follow the large, early money rather than the news. The third is copy-trading: mirror the trades of traders whose record you can verify, instead of building your own.

Copy-trading exists because every trade is public. A tool like PolyCopy watches a trader you pick and repeats their trades on your account, capped by your own limits, after you have tested the approach on virtual money first.

Common questions

Is Polymarket gambling?

It is closer to a financial market than to a casino: you trade against other people rather than against the house, prices are set by supply and demand, and outcomes are settled against real-world events. That said, it carries real risk of losing money, and the same caution applies.

How do I get started?

Create an account, deposit USDC, pick a market and buy a side. If you want to test the idea without money first, a paper-mode copy-trading tool lets you mirror real traders on virtual money before risking anything.

Can the price be manipulated?

On thin markets with little volume, a large order can move the price temporarily, which is why small markets behave differently from liquid ones. On liquid markets the price is harder to move and usually reflects real information.

Is it legal everywhere?

No. Polymarket restricts access from several jurisdictions, and the rules differ by country. Check whether prediction-market trading is permitted where you live before depositing.

Written from the mechanics of Polymarket markets: binary shares priced $0–$1, YES/NO prices summing to one, on-chain settlement against a written resolution source, and public trade history.

Originally published at poly-copy.net.