The "Trump trade" now runs on earnings — and the bond market sets its clock

The "Trump trade" is usually spoken of as a wager on the future: lower taxes, lighter regulation, cheaper money. Yet the version that is hot this September is no longer a bet on promises at all. Since the 2024 election the S&P 500 has returned more than 36%, and the engine is not expectation but delivered profit — second-quarter earnings grew by more than half on a year earlier, on revenue up more than a sixth, at record margins, and the rally has broadened far beyond the technology giants that first carried it. This is a trade that has banked its thesis and is now being paid for performance.

The trouble is that the performance was bought with borrowed money, and the bill is arriving in the bond market.

A boom financed on credit

The tax-and-spending bill known as the One Big Beautiful Bill Act is estimated to add $3.4 trillion to federal debt over the coming decade. Total federal debt has already passed $40 trillion. The average interest rate the Treasury pays on its marketable debt has more than doubled since early 2022, to 3.44%. That arithmetic is working its way through the market: the 10-year Treasury yield has crept toward 5%, nearing the psychologically critical 5% level, even as stocks sit near a record. Fixed-income investors, in other words, want more compensation for the mountain of borrowing that underwrote the profit boom.

That is the first crack in the trade. A bull market can live on earnings alone; it struggles when the discount rate applied to those earnings rises at the same time. A 10-year yield that keeps climbing makes bonds genuinely competitive with stocks for the first time in years, and lifts the cost of the corporate and consumer credit that funds the growth on which the earnings boom depends.

A fight over the one lever left

The administration's other levers are shorter than they were. In February the Supreme Court struck down the emergency tariffs imposed under the International Emergency Economic Powers Act, and the resulting refund fight runs to the hundreds of billions of dollars. A president who cannot easily tax imports is leaning on the one institution that can still move the cost of money: the Federal Reserve.

On September 4, in the wake of a much-stronger-than-expected jobs report, President Donald Trump demanded that the Fed slash rates, declaring that a strong country means a lower interest rate — or else, he said, he would cut off trade with countries that run surpluses against America. The "great new leader" he addressed, Kevin Warsh, has declined the invitation. Warsh took over as Fed chair in May and has said he intends to "deliver price stability" rather than race to ease. The Fed left rates unchanged in July, three members voting for an increase; by last week traders put a better-than-even chance of a hike at the September meeting.

Here is the irony the market must digest. The Trump trade's longevity no longer depends on the White House at all; it depends on whether the Fed holds its course. If the Fed stands firm, higher long yields do the tightening themselves, slowly torquing the equity multiple the trade relies on. If the Fed blinks under pressure, the bond market exacts the price through worse inflation and a blown-out yield curve. Either way, the cheap money that financed the boom is being priced out — and the institution whose credibility keeps the whole structure from breaking is precisely the one the president is now assaulting.

Investors would do well to separate the two halves of their winnings. The earnings boom is real and at least partly durable. The valuation that sits on top of it was bought with borrowed fiscal firepower, and its cost is rising month by month. When a rally is paid for by deficits, the bond market is the timer — and the political assault on the central bank is what is setting it running.