A Polymarket limit order needs at least 5 shares before it will even post to the order book. A market order has no such floor, but it also has no price protection — it fills against whatever is sitting in the book right now, even if that’s far worse than the price you saw a second earlier. That single difference is why a polymarket limit order becomes the default tool for anyone who has been burned once by a thin, fast-moving market.
Market Order vs. Limit Order: What Actually Changes
A market order says “fill me now, at whatever price is available.” On a liquid market like a major election contract, that’s usually fine — the spread is tight and the price barely moves. On a thin market, a market order can walk straight through three or four price levels before it’s fully filled.
A limit order says “fill me at this price or better, and nothing worse.” You pick the exact price. If the market doesn’t come to you, the order simply sits unfilled on the book instead of forcing a bad trade. We broke down why that gap between the best bid and the best ask matters so much in our guide to Polymarket’s bid-ask spread — a limit order is the practical tool traders use to stay on the right side of that spread.
How to Place One
On Polymarket’s trading screen, you switch the order type from Market to Limit, pick Buy or Sell, select the outcome share you want, and then set a limit price using the price field or the +/- buttons. Below that, you enter the share count — the minimum is 5 shares for a limit order, with no such minimum for a market order.
According to Polymarket’s own trading documentation, the limit price you set is the maximum you’ll pay on a buy, or the minimum you’ll accept on a sell. The order can fill fully, fill partially and leave the rest open, or never fill at all if the market never reaches your price.
Good-Til-Cancelled vs. Good-Til-Date
By default, a limit order on Polymarket stays open until it fills or you cancel it manually — that’s Good Til Cancelled (GTC). You can also set an expiration instead: 1 minute, 5 minutes, 1 hour, 12 hours, 24 hours, or end of day. That’s Good Til Date (GTD), and the order cancels itself automatically once the clock runs out.
GTD is useful around scheduled events. If you’re placing a price bet ahead of a data release or a game result and you don’t want a stale order sitting on the book afterward, a short expiration window removes the need to remember to cancel it yourself.
Why Limit Orders Also Pay You
Placing a limit order that doesn’t fill immediately means you’re adding liquidity to the book rather than taking it. On many Polymarket markets, that qualifies you for a maker rebate — a small payment for resting your order instead of crossing the spread. We go through the mechanics, caps, and category differences in our maker rebate program breakdown.
This is the part that gets missed by traders who only ever use market orders: a limit order isn’t just a defensive tool against bad fills. On active markets, it can turn the fee structure in your favor instead of against it.
When a Limit Order Can Backfire
A limit order’s biggest weakness is simple — it might never fill. If you set your price too far from the market and the price moves away instead of toward you, your order just sits there, unfilled, while the opportunity passes.
This matters most around news events. If a market is about to move hard in one direction — a debate, an earnings call, a match result — a limit order parked at yesterday’s price can miss the move entirely while a market order would have gotten you in, even at a slightly worse price. The tradeoff is price control versus certainty of execution, and there’s no version of an order type that gives you both.
There’s also a practical sizing issue. Because limit orders need a 5-share minimum, you can’t use one to make a token-sized test trade smaller than that. For very small positions on illiquid markets, a market order may be the only option, bad fill risk and all.
A Simple Rule of Thumb
Use a limit order whenever you have a specific price in mind and the market isn’t about to move violently in the next few minutes. Use a market order when speed matters more than price — you need to be filled right now, and you’re willing to pay for that certainty.
Most experienced Polymarket traders default to limit orders and reach for market orders only when a market is thin, fast-moving, or both. Once you’ve watched a market order eat through three price levels on a low-volume contract, the appeal of setting your own price stops being theoretical.
