Bowman's Stress-Test Finale Resets the Capital Math — Banks Win, Critics Sue

Vice Chair for Supervision Michelle Bowman used her Sept 18 Mansion House speech — titled \"The Final Chapter on Modernizing Bank Regulatory Stress Testing\" — to telegraph the last major rewrite of the post-2009 supervisory regime before the Fed votes on a final version \"in the coming weeks.\" The package layers four changes onto the current rule: full disclosure of model equations, variables and coefficients; public comment on the hypothetical scenario itself (starting with the 2026 cycle); a balance-sheet \"freeze\" date so banks know exactly which book of business is being tested; and — most consequential for buyback math — an SCB built on the average of a bank's two most recent annual results rather than a single year's swing.

Bowman framed the overhaul as the end of an \"opaque and unnecessarily unpredictable\" framework that has drawn two federal lawsuits and a withering Wall Street complaint since 2024. Her timing is deliberate: the Fed Board meets this fall on the parallel risk-based capital rules, with the GSIB surcharge and Basel revisions expected to finalize by year-end. The Fed's March 19, 2026 proposal already cut aggregate capital requirements for the largest banks by 4.8% — roughly five times the 1.6 percentage-point CET1 depletion the 2026 stress test projects under the severely adverse scenario.

Buried in the speech is a separate proposal — open for comment now — to replace the existing noninterest-income model for the 2027 stress test. The model is what the Fed uses to penalize trading, investment-banking and wealth-management revenue inside a recession scenario, and the current version has long been criticized for treating a Goldman Sachs trading desk and a Wells Fargo branch network as interchangeable fee streams. Bowman explicitly said the revised model is intended \"to better capture business diversity across firms.\"

That phrasing is aimed directly at Goldman Sachs and Morgan Stanley — the two U.S. banks whose SCBs sit well above the 2.5% floor (3.4% and 4.3%, respectively, per the Fed's June 24, 2026 Large Bank Capital Requirements disclosure). A model that recognizes the offsetting nature of trading revenue and capital-markets fees against drawdowns could shave basis points off the SCBs of the most capital-markets-heavy firms — and it is the single reform most likely to show up in 2027 buyback authorizations, not the headline transparency rules.

The June 24, 2026 stress test results — the dataset the buyback market already digested in July — remain the baseline against which Bowman's reform is being priced. All 32 participating banks stayed above minimums under a severely adverse global recession: aggregate peak-to-trough CET1 depletion was 1.6 percentage points (vs. 1.8 pp in 2025), with the aggregate CET1 ratio projected to fall from 12.8% to a 11.2% trough before recovering to 12.7%.

The Fed froze 2026 SCBs at 2025 levels in February 2026, which is why Bank of America and JPMorgan Chase could announce fresh buybacks the day results dropped. But the freeze is a one-year bridge: the 2027 SCBs — set next June — are the first numbers that will reflect Bowman's new averaging rule, and they are what will define the next buyback cycle.

Eight days before Bowman's speech, Better Markets filed a32-page complaint in the U.S. District Court for D.C. (Case 1:26-cv-03163) naming both the Federal Reserve Board and Bowman personally. The suit alleges Bowman and other Fed officials \"secretly met with the CEOs of Wall Street's biggest, most dangerous banks — including JPMorgan Chase CEO Jamie Dimon and Goldman Sachs CEO David Solomon — and corruptly coached, directed, and coordinated with them\" during the open comment period on the March 2026 capital proposal.

The complaint seeks declaratory and injunctive relief — specifically, withdrawal of the March proposal and an order recusing Bowman from the rulemaking. It is not a damages action; there is no monetary demand. The relief asked is procedural, but the financial stakes ride on it: if a court vacates the capital-rule rollout, the 4.8% GSIB relief, the GSIB surcharge revision and the new SCB averaging rule all lose their statutory anchor — even though the stress-test transparency reforms sit on a separate rulemaking track. Banks and trade groups filed their parallel procedural challenge to the Fed's stress-test opacity on Dec. 24, 2024, and that litigation was extended through Oct. 15, 2025, on a court-issued pause.

Four days before Bowman's speech — and a week after the lawsuit — Bank of America CEO Brian Moynihan told the Barclays Global Financial Services Conference that Q3 investment-banking fees would come in at $1.6B to $1.8B, down from $2.0B a year earlier, with sales-and-trading revenue \"roughly flat.\" At the low end that is a 20% year-over-year drop in IB fees — the line that the Fed's noninterest-income model writes down hardest in any recession scenario. The Q22026 result Bank of America just reported was $49.4B in revenue and $9.1B in net income, so the IB-fee shortfall is roughly 2–3% of total revenue but a much larger share of the segment that drives the SCB math.

Read together, the three events describe a tension investors should not miss. The Fed is about to make bank capital requirements smaller, more transparent and more predictable — exactly what the IB-heavy banks asked for in their December 2024 lawsuit. But the same firms are guiding to a quarter in which the IB revenue they are being asked to keep capital against is shrinking sharply. Lower capital charges against a shrinking fee pool is a wash on margin; against a growing fee pool it is the kind of tailwind that pulls forward buyback authorizations. The current setup is closer to the former.

Bowman's reform package is most under-priced as an M&A enabler rather than a buyback enabler. The same March 2026 proposal that cuts aggregate GSIB capital by 4.8% also loosens how the GSIB surcharge is measured and calibrated — directly enlarging the deal capacity of the five U.S. GSIBs. Two regional-bank tuck-ins already landed in early 2026 (U.S. Bancorp's BTIG purchase for capital-markets capability being the most cited), and one bank is widely expected to cross the $1 trillion asset threshold via acquisition during this cycle.

For JPMorgan Chase — the only GSIB whose CET1 requirement (11.5%) sits above Bank of America's 10.0% despite identical SCBs of 2.5% — the combination of a 4.8% GSIB relief and a more predictable SCB trajectory is the difference between a constrained and an unconstrained deal pipeline. For Wells Fargo, the math is similar in percentage terms but partly offset by the asset cap that still binds the franchise from its2018 consent orders. For Citigroup, the SCB is higher (3.6%) and the transformation story is execution-driven, so the regulatory relief is a tailwind that has to clear the operational turn first.

Short-term (days to quarters), three dates matter: the Fed's final stress-test rule vote in the \"coming weeks\" Bowman signaled — most plausibly an October open Board meeting, the same forum that produced the Oct. 24, 2025 transparency proposals; the year-end capital-rule finalization for the GSIB surcharge and Basel revisions; and the Better Markets case's first substantive court ruling. Any procedural loss by Better Markets would slow, not stop, the buyback cycle because the SCB freeze runs through 2027 regardless.

Long-term (one to three years), the structural shift is the move from a one-year to a two-year SCB average, the disclosure of model coefficients, and a balance-sheet freeze date that turns stress testing into something banks can model against. If the 2027 noninterest-income model revision lands as described, Goldman Sachs and Morgan Stanley — both currently above 3% SCBs while the rest of the GSIB cluster sits at 2.5% — see the most asymmetric upside. If the lawsuit stalls the rule, the buyback pause that capital volatility forces also returns, and the M&A capacity expansion slips a year.