The most profitable way to play a boom is sometimes to lend to the people placing the bets. That is the story inside Wall Street's equities desks this year. The five biggest investment banks booked roughly $67 billion in equities revenue through September 30, about $7 billion more than they earned in all of 2025, which was itself a record. The long-term question for shareholders is how much of that is durable franchise and how much is leverage riding a theme.
The gains are concentrated. Goldman Sachs, JPMorgan Chase and Morgan Stanley account for about $52 billion of the total, close to 80%. The engine is prime brokerage: margin loans, securities lending and trading services for hedge funds. Goldman's equities financing revenue jumped 96% in the third quarter to a record $3.37 billion, and JPMorgan's CFO described the appetite for capital as insatiable. Executives argue this has turned equity desks from cyclical, transaction-driven businesses into steadier, higher-margin lending operations.
There is a real moat here. Prime brokerage rewards scale, because a hedge fund wants one counterparty that can absorb a large position and keep serving it across regions in stressed markets. The biggest banks can take a $100 million trading loss without wrecking a quarter. Smaller or more specialized rivals cannot, so they pass on the business or lose share. Bank of America and Citigroup are already trailing the leaders in this arena, which shows how fast scale advantages can compound once a cycle turns up.
The caveats matter just as much for a patient owner. Part of the surge reflects regulators easing leverage rules for the largest banks, which frees balance sheet for exactly this kind of lending. Stanford's Darrell Duffie said the system is somewhat more levered as a result, calling it not a good idea even if things have not gotten dramatically out of whack. The IMF warned this month about crowded positions and correlated selling among hedge funds, whose assets it puts near $13 trillion, and Jamie Dimon has said industry leverage is the highest it has ever been. Some Asian revenue is also inflated by transaction taxes and stamp duties, and banks do not define equities revenue the same way, so comparisons are fuzzy.
So what for long-term investors? Record trading profit tells you about the cycle, not the franchise. Earnings tied to hedge fund leverage on a single theme can reverse quickly if the AI trade stumbles, and analysts note the Big Three would feel that more than most. Owners of bank stocks, directly or through index funds, should look past peak-year results to through-the-cycle returns on equity, capital buffers and dividend coverage. A business that earns outsized profit lending against collateral is attractive. The test is whether it still earns its keep after the next margin-call season, and no single record quarter can answer that.