Learn
Why a copier keeps less than the trader they copy, and how we check our numbers. Start with the methodology.
- Copy Trading Slippage on Polymarket: Why a Late Copy Pays MoreWhat slippage and delay cost mean for a Polymarket copy trader, how FollowCheck measures them from real on-chain fills, and what changes the simulated cost.
- Polymarket Taker Fees in 2026 and What They Cost a Copy TraderWhy copy traders on Polymarket almost always pay taker fees, how FollowCheck includes them in every backtest, and where fees show up in the results.
- Out-of-Sample Testing: Why Last Month's Best Traders Often Stop WinningWhy FollowCheck shows out-of-sample results next to every ranked trader, and how to read the out-of-sample columns on copyability boards.
- Data Reconciliation: How FollowCheck Checks Its Polymarket Trade DataHow FollowCheck reconciles indexed on-chain fills against Polymarket's own trade records every day, and how you can verify any trade yourself.