The mechanism. On March 19, 2026, the Federal Reserve, OCC, and FDIC re-proposed the Basel III Endgame — junking the 2023 draft that would have jacked up capital requirements by roughly 19% for the largest banks. The rewrite recalibrates the Fundamental Review of the Trading Book (FRTB), the framework that sets market-risk capital charges, and applies it "only to banks with significant trading activity." The agencies project aggregate capital requirements for Category I banks will fall modestly — the Fed itself has floated a capital-neutral-to-negative outcome. That's the opposite of the 2023 version, which threatened to make trading and underwriting meaningfully more capital-expensive. Comments closed June 18, 2026; a final rule is the next catalyst, and it lands unevenly by business mix — banks with the most risk-weighted assets tied to trading desks get the biggest swing.