Last nights prediction markets on the election were heavily traded relative to past PMs. Predictit alone had hundreds of millions of USD in trade volume. Many LWers competed on the markets, for reasons discussed here. If you competed, share your experience here.
FTX fees are .07% per trade if you take liquidity or 0 if you add liquidity. I paid somewhere under 1% to get the money from IBKR into my bank then into Coinbase then into FTX.
Betting on FTX is not allowed for US residents. I'm a US person but not a US resident, which gives me more options for prediction markets than most people. I heard some US residents were betting on Catnip. While FTX is a web site that lets people trade cryptocurrency balances held by FTX, Catnip is a decentralized market, so in some sense it's more of a "real" crypto betting market than FTX.