Woofun AI reports that Polymarket has integrated the Spark protocol to enable instant, self-custodied Bitcoin deposits via the Lightning Network. This update replaces the previous on-chain method requiring 3 to 6 block confirmations, reducing deposit times from 10 to 60 minutes to mere seconds while lowering transaction costs.

The Spark protocol performs double-spending and fee checks at broadcast, allowing "zero-confirmation" crediting across on-chain, Lightning, and stablecoin channels without Polymarket operating nodes. The platform stated this enhances capital efficiency for Bitcoin users and strengthens competitiveness against Kalshi.