[convexly]

That claim is testable. The 2026 microstructure work on the Kalshi tape (72M trades, Becker) documented a systematic +1.12% excess return for liquidity providing makers and a symmetric -1.12% for takers, plus a longshot bias where 1-cent yes shares pay -41% EV and 1-cent no shares pay +23% EV. That edge is in the market microstructure layer. A patient maker who never trades the frontpage market makes money on the marginal bidder asymmetry alone.

Akey, Gregoire, Harvie, Martineau (2026) on Polymarket find that the top 1% of wallets capture about 84% of all profits, and that the largest whale wallets are NOT the most sophisticated. Large capital systematically bleeds expected value to small order traders. Reichenbach and Walther (2025) document within-Polymarket skill persistence at the 124M-trade scale, so skill differentials are measurable across users distinct from the insider trading question.