Okay, we all know that the current rally that has pushed U.S. equities to one record after another is built on cheap money. That is on a Federal Reserve that has promised to cut interest rates one, two, or maybe even three times in 2019. And on a hope on Wall Street that the 2019 cuts won’t be the end of the rate reduction cycle.

The Federal Reserve, of course, isn’t alone. The Bank of Japan is committed to  below zero interest rates. And European Central Bank, despite flirtations with positive interest rates, seems locked in to below 0% benchmarks.

Debt cycles do come to an end–frequently not very pretty end–when for some reason lenders decide that they can’t just keep on lending. That results in what has been dubbed a Minsky Moment in honor of economist Hyman Minsky who pioneered the idea of the inherent instability of the debt cycle in capitalist systems. The usual reason, Minsky posited, is that lenders, having lent with looser and looser, and riskier and risker standards during good times in the economic cycle, suddenly decide to lock the door to the vault after all the cash has escaped. The tighter lending standards then put in place pretty much guarantee that the resulting collapse will be severe. (The Global Financial Crisis set off by the subprime mortgage lending bubble is an extreme example.) The bigger the bulge in debt on the upside, the more severe the consequences are on the downside.

Which is why the continuing increase in global debt makes me nervous–and why it should make you nervous too. Despite–or maybe because of–historic highs in the equity indexes.

In the first quarter of 2019, global debt levels jumped to a level matching last year’s record increase in global debt, according to the Institute of International Finance.

Debt rose by $3 trillion in the period to $246.5 trillion, almost 320% of global economic output, the institute said in a report published last week. Measured in dollars that’s the second-highest dollar number on record after the first three months of 2018. In percentage of global GDP debt was higher in 2016 and 2017 as a share of world GDP.

Emerging-market borrowing rose to new record of $69 trillion, while debt in developed countries increased by $1.6 trillion in the quarter to $177 trillion. That includes $69 trillion in borrowing in the United States where, the report notes,  government borrowing has been on the rise.(One way to put it, I suppose.)

Conditions in China’s non-financial sectors have actually improved as Chinese companies continue to trim their large debt loads. burden, Debt held by non-financial corporations declined to 155.6% of GDP from 158.3% a year earlier. That’s still more than twice the U.S. debt to GDP level for non-financial corporations.

Emerging markets, in general however, remain a focus for concern since companies in those economies are increasingly relying on short-term borrowing which “leaves some highly indebted firms more exposed to swings in global risk appetite,” the report notes.