Polymarket has added a new feature called combo trading, which lets users bundle several predictions into a single position. The product went live around June 10 and is initially limited to sports markets.
Each selection in a combo must resolve in the trader’s favor. One wrong prediction voids the entire ticket. This setup offers a chance for higher returns compared to entering each market separately, but it also carries increased risk.
The first version covers only sports contracts, including moneyline, spread, and total markets. Polymarket announced the release on X with the line, “combos are now live.” The company hasn’t provided a timeline for adding politics, breaking news, or other event markets, which remain outside this product for now.
How Combo Trading Works
Polymarket doesn’t place combo orders on its regular open order book. Instead, it uses a request-for-quote, or RFQ, process. After a trader submits an order, market makers have 400 milliseconds to quote a price. The trader then gets five seconds to accept the best quote. Some market makers can also activate Last Look, a feature that gives the liquidity provider a final one-second window to accept or reject the fill.
This RFQ approach is common in traditional finance for instruments that are hard to price or don’t trade well through passive matching. By assigning liquidity providers to price the whole group of outcomes at once, Polymarket aims to handle combos more efficiently.
API Access and Strategy
Polymarket has also opened a public API endpoint for combo markets. Developers don’t need the standard authentication tied to the platform’s central limit order book to access it. This means outside analytics services, trading dashboards, and other software can pull combo data without the usual login process.
For traders, the feature allows them to group events they see as connected. Someone with a broad view on sports can act on that perspective with one trade instead of placing and monitoring multiple individual bets. The structure might also appeal to people familiar with sportsbook parlays but new to prediction markets.
Unanswered Questions and Risks
Some details about the initial release remain unclear. Traders still need to know which specific sports contracts can be added to a combo. Polymarket hasn’t clarified how fees apply across multiple legs or how settlement works when one outcome resolves before others do.
There’s also the possibility that liquidity for combos could be thinner than for single-outcome markets. With fewer market makers involved, bid-ask spreads might widen, leading to poorer execution. Adding politics and other events would broaden the product’s appeal, but the company hasn’t said when that might happen. The sports-only launch gives Polymarket room to test pricing, settlement, liquidity, and demand before rolling out combos site-wide.
Background Competition with Kalshi
This move comes about a month after a controversy where Polymarket investigated whether rival platform Kalshi was copying its business model. A document titled ‘Copycat’ contained around 12 items that Polymarket believed matched its own product releases too closely. Both platforms compete over contracts related to sports, weather, and geopolitical events.
Matthew Modabber, Polymarket’s head of marketing, confirmed the review during a phone interview. “There have been a couple too many coincidences,” he said. Another Polymarket executive accused Kalshi of acting intentionally, stating, “There is bad intention in how they copy us. They’re breathing down our neck.”
