Hi all. I built this because prediction markets got huge this year and nobody sends you a tax form for any of it. Kalshi gives you a CSV of individual fills, Robinhood gives you a statement that says on it that it is not a tax form, and Polymarket gives you nothing whatsoever. In April every one of those becomes your problem. The part that surprised me most was Polymarket. When a position wins you redeem it, because each share pays a dollar, and that redemption is written to the chain. When a position loses, redeeming pays nothing and still costs gas, so essentially nobody does it and the loss leaves no record at all. Every leaderboard and tracker built on settlement data is therefore counting wins far more reliably than losses. I have rebuilt twelve wallets from the top of the weekly profit board to see how big the gap gets. Their real win rates land between 44 and 74 percent, so this is not a story about everyone secretly being average. Some of them are genuinely good. What has not varied once is the direction. All twelve profiles read higher than the rebuilt record, by anywhere from 12 points to 52. One profile shows 200 wins against 1 loss for a trader who is really 200 and 222. Another shows 33 wins and no losses at all, for a trader who is 33 and 23. So a published win rate is a ceiling rather than a measurement, and from outside you cannot tell whether a given one is off by twelve points or by fifty. They are all genuinely up a lot of money. For most of them the edge is position sizing rather than accuracy, which is a much harder thing to copy than a win rate. It is free and it has no account because there is no server to hold anything: parsing, lot matching and export all happen in the page. You can watch the network tab while you import. Two things I would ask. If you trade these markets, tell me where it gets your numbers wrong, because it has been tested against files I wrote far more than against real ones. And if you know how any of this should actually be filed, I would love to hear it, because the classification of event contracts is genuinely unsettled and I have been careful not to pretend otherwise anywhere on the site.

Whalefax

The tax report Kalshi and Polymarket never send you

The tax report Kalshi and Polymarket never send you