There’s a time bomb in Donald Trump’s economy, and it’s likely to detonate before 2020.

Of course, it’s hard to see right now. His trade war with China notwithstanding, the economy seems to be the brightest star in the Trumpian universe. Despite the last few days, the stock market remains at all-time highs. Annualized G.D.P. is forecast to be a respectable 3.2 percent. The falling unemployment rate—which Trump derided as fake news until he took office—is at 3.6 percent, the lowest in nearly 50 years. Trump has even succeeded in jawboning Jerome Powell, the chairman of the Federal Reserve Board, into backing off his plan to raise short-term interest rates. As a result, interest rates—which determine what it costs Americans to get a mortgage or a car loan—remain historically, and unnaturally, low. An economy this good, many Democrats worry, could even get Trump re-elected, insane as that might seem.

But the economic picture is more complicated. On the one hand, Trump can lay a legitimate claim to having once again unleashed the “animal spirits” across the land. He has greatly reduced corporate tax rates and regulations, giving businesses a much freer rein to do pretty much whatever they want in search of more and more profit. And he is doing his level best—and succeeding, at least temporarily—in keeping interest rates lower than they otherwise would be but for his ongoing meddling into the affairs of the Federal Reserve.

Ironically, the very actions that Trump has taken, and that he believes are responsible for supercharging the economy (which I must hasten to point out was already doing pretty well under Barack Obama), will come back to haunt him. There’s always a price to pay when capitalists are allowed to roam free without supervision. But the real problem for Trump will come from his Fed gambits. By keeping interest rates at artificially low levels for so long (it’s been nearly 11 years and counting), debt investors are on a worldwide hunt for higher yields—the so-called “yield-hunger games”—forcing them to overpay for bonds, loans, and other debt-like instruments, and to take higher and higher risk without getting properly compensated for them.

When the economy turns—and it will; it always does—investors will lose hundreds of billions of dollars as a result of mispricing risk. “At this point, there’s more actual risk exposure than Trump would have you believe,” says one senior Wall Street banker, a friend of mine. “The world is more leveraged than it has ever been before at the corporate level, at the sovereign level, and collectively at the consumer level.”

Wall Street has always been very good at providing investors with what they want. If they want higher-yielding bonds, loans, and debt securities, then that’s exactly what Wall Street will start manufacturing and selling. You will remember, no doubt, that’s exactly what happened more than a decade ago when Wall Street started manufacturing and selling mortgage-backed securities that promised higher yields for AAA-rated credits. Of course, that was a chimera. And it all ended very badly, in the worst financial crisis in memory.

Now, Wall Street is inventing a new generation of risky instruments, of which there are many, many examples. From loans issued without covenants, to risky loans packaged up as securities and sold around the world as good investments, to “junk bonds” that yield 6 percent when they should be yielding closer to 10 percent or more.

One such symptom of the current situation, which arrived in my inbox the other day: an offer for a so-called “structured investment,” courtesy of the geniuses at JPMorgan Chase. What they have successfully served up to investors, hungry for yield, is a six-month note that promises to pay investors annualized interest of 16 percent under certain circumstances. Those certain circumstances depend almost entirely—believe it or not—on the performance of G.E.’s stock. As long as G.E.’s stock stays within a certain range each month for six months—basically not falling more than 30 percent from roughly where it has been—then JPMorgan Chase will pay investors at least 1.333 percent per month interest on their investment, or 8 percent for six months, or an annualized rate of 16 percent.