Biden’s April 2021 American Families Plan explicitly proposed taxing long‑term capital gains and dividends for households with more than $1 million of income at the ordinary top rate of 39.6%, nearly doubling the then‑top 20% capital‑gains rate (43.4% including the 3.8% NIIT).(bidenwhitehouse.archives.gov) However, that plan was never enacted as introduced; major components of the American Families Plan ended up in the failed Build Back Better negotiations, and key planks (like its flagship family and leave provisions) "have not become law."(washingtonpost.com)

As of tax years 2025 and 2026, federal long‑term capital gains are still taxed at preferential rates of 0%, 15%, or 20%, with only the income thresholds indexed for inflation; no 39.6% long‑term capital‑gains bracket exists in current law.(kiplinger.com) In other words, the specific Biden proposal to tax long‑term capital gains for million‑plus earners at 39.6% (roughly doubling the top rate) was never enacted.

Given that the prediction was about that specific near‑doubling of the top long‑term capital‑gains rate not becoming law, and more than four years have now passed with the old 0/15/20 structure still in place, Chamath’s prediction matches the outcome.