Stocks just broke through a key level that indicates a sell-off. Here’s how much the S&P 500 will fall before you should buy, according to one strategist

• Stocks broke a key level that suggests a 5% sell-off is coming, BTIG’s chief market technician says.

• The S&P 500 saw resistance around 6,100 at the start of the year.

• There are 4 reasons the index could retest that level, he added.

The stock market flashed a key technical signal that suggests a pullback from all-time highs is on the way.

That’s according to Jonathan Krinsky, the managing director and chief market technician at BTIG, who thinks the S&P 500 is bound for a 5% pullback soon. The benchmark index just broke through a technical resistance level that suggests a retrenchment is likely, he said, speculating the index could fall to around 6,100 before investors have the opportunity to buy.

The S&P 500 saw technical resistance, a price ceiling where sellers are likely to step in and cause a pullback, at around the 6,100 mark in late January, Krinsky said. That was several months before Trump announced his tariffs and drove a steep decline in equities. The index then dropped around 20% from its February peak through the sell-off in early April, before breaking past the key 6,100 level again in late June.

“Typically, when you break through resistance, you do get a check back to kind of retest that support. And so we do think that’s coming, into this August, September period,” Krinsky said, speaking to CNBC this week. “We think you’ll get an opportunity to buy around 6,100.”

There are a few signs that suggest that the stock market is looking vulnerable to a correction, Krinsky added. Here are some of the warning signs he sees:

Krinsky pointed to potential vulnerabilities in consumer-facing sectors, like retail and transportation.

The consumer discretionary sector of the S&P 500, for instance, has been among the worst-performing areas of the market so far this year. Consumer discretionary stocks in the S&P 500 are down 0.43% since January, one of the only areas of the broader index in the red this year.

Other market pros have said they’re eyeing weakness in consumer stocks, pointing to the impact of tariffs on inflation and consumer spending.

“You’re seeing some cracks under the surface,” Krinsky said.

Historically, semiconductor stocks have lagged behind software stocks in the late summer, Krinsky said, adding that he believed many names in the semiconductor space also looked vulnerable to him.

Some chipmakers’ second-quarter earnings have been weaker than expected. Advanced Micro Devices missed slightly on earnings estimates for the quarter, while Super Micro Computer missed slightly on earnings and revenue.