Polymarket, the world’s largest prediction market, has switched on instant bitcoin deposits over the Lightning Network, with new rails powered by the Spark protocol crediting funds in under one second.
Opening up new avenues
The upgrade replaces a funding flow that previously took anywhere from 10 to 60 minutes, now settling deposits almost instantly with near-zero fees.
It marks a sharp departure from the standard onchain bitcoin deposits Polymarket added in October 2025, which required three to six network confirmations before crediting an account.
Those onchain deposits carried a higher minimum reflecting bridging costs, but the Lightning route settles in seconds while keeping minimums low.
Tether CEO Paolo Ardoino, whose company issues USDT, praised the underlying technology, describing it as:
“A route to programmable Bitcoin over Lightning.”
How Spark’s rails work
Spark was developed by Lightspark and is built on statechain technology, a design that moves bitcoin ownership off the main chain while preserving user custody.
The protocol validates a bitcoin transaction the moment it is broadcast, checking for double-spend risk, fee adequacy, and replace-by-fee flags before crediting the deposit.
The structure also lightens Polymarket’s operational load, since it no longer has to manage confirmation thresholds or run its own Lightning nodes.
Deposits remain self-custodial, with each wallet tied to the user’s own keys, so traders keep control of their funds until they place a trade.
Wallet providers including Breez, Xverse, and Cake are also building on the protocol.
A funding race with Kalshi
The upgrade lands in the middle of an intensifying battle for prediction market volume, with rival Kalshi posting $5.42 billion in April taker volume, overtaking Polymarket’s $1.99 billion for the first time as the sector’s monthly total hit $8.6 billion.
Polymarket also recently unveiled perpetual futures trading for U.S. markets, broadening its offering beyond simple event contracts as it works to reclaim ground.
