Kalshi, Polymarket and Robinhood do not send a 1099 for event contract trades, so the record you file in April is yours to build. Whalefax turns any of their exports into real P&L and per-position tax detail, with FIFO lot matching and fees in the right place. It also rebuilds any public Polymarket wallet, including the losing positions that leave no trace on chain. Free, no account, and it runs entirely in your browser so your trades are never uploaded.
