Polymarket is introducing a technical change to reduce automated gaming on its platform. From 5 Jun, taker orders on its crypto and finance markets will be locked once they enter a 250-millisecond delay window, preventing cancellation until the delay period completes.
The update, announced by the platform’s developer account on X, applies to up/down markets on crypto and financial assets. Once an order passes initial validation and enters the delay window, it becomes pending and irrevocable. Cancel requests during this period will be rejected.
Held balances will be reserved against other orders from the same account until the delayed order resolves. Resubmitting the same order or dropping a connection after it enters the delay will not prevent execution.
Polymarket’s short-duration crypto markets have seen strong retail interest. Five-minute Bitcoin (BTC) and Ether (ETH) contracts generated more than $200mn in trading volume in a single week as of February.
Why speed bumps matter
The 250-millisecond taker delay acts as a speed bump – a mechanism designed to level the playing field. In traditional markets, similar delays were introduced by venues such as IEX to counter high-frequency trading advantages.
In prediction markets, automated bots can currently submit and cancel orders in microseconds to probe liquidity and extract information before slower participants react. By making orders irrevocable once they enter the delay window, Polymarket aims to close this loophole and reduce low-risk speculative probing by algorithms.
TradFi piles in
The change comes as prediction markets mature and attract greater institutional participation. The Commodity Futures Trading Commission (CFTC) cleared Kalshi’s BTCPERP contract on 29 May, marking the first US-regulated crypto perpetual. Coinbase also received a no-action letter to route US clients to Deribit’s derivatives markets.
Monthly prediction market volumes recently exceeded $20bn, according to TRM Labs. Galaxy Digital introduced an institutional over-the-counter prediction markets desk on 2 Jun, while firms such as Jane Street and Hudson River Trading have become active on Kalshi.
