Worried about a market crash with stocks at all-time highs? History says don't be.

With stock market indexes sitting just off all-time highs, it can be easy to develop a fear of heights.

What if things suddenly go wrong, and stocks tumble down the mountainside, erasing your gains?

It’s a normal concern, says AllianceBernstein, which manages $785 billion in assets. But in a recent analysis, the firm found that market rallies usually continue in the years after a fresh peak is notched.

“It’s a common belief that when markets reach new peaks, a downturn is just around the corner. This mindset can make investors hesitant to initiate or increase their equity exposure,” the firm said in a recent report. “Yet our analysis of more than 11,000 trading days since 1980 tells a different story.”

Over the last 45 years, if one were to invest on a day when the S&P 500 reached an all-time high, they would have seen an average one-year return of 10.5%. That’s the same average return they would have seen after investing on any given day. For both categories, the probability of seeing a positive return was 78%.

Over a three-year period following investing on a day when the index hit a new high, returns averaged 36.7%, beating the average 33.8% return for any random trading day. There’s been an 87% chance that returns were positive three years after investing at an all-time high, and a 94% chance for any trading day.

AllianceBernstein said earnings growth is responsible for the pattern.

“Equity markets may face volatility for various reasons, from macroeconomic stress to geopolitical turmoil. Yet over the long term, stock prices are ultimately driven by earnings performance,” the firm said. “And when earnings are on the rise, they typically don’t halt abruptly. Instead, they continue to grow, until they gradually decelerate.”

While the data favors further upside, every cycle is different, and negative outcomes are possible. One growing risk to the market’s advance appears to be a weakening labor market. The US added just 22,000 jobs in August, the Bureau of Labor Statistics said on Friday, continuing a four-month stretch of tepid job growth. Though the unemployment rate rose just slightly, stocks fell on Friday on the news.

Inflation has also proven difficult to bring down to 2%, and tariffs threaten to drive consumer prices up higher. This has halted the Federal Reserve’s rate-cutting cycle this year, though the central bank is expected to slash its benchmark rate at its September meeting.

Despite the risks, Mo Haghbin, head of strategic ETFs at ProShares, told Business Insider on Friday that the rally is likely safe for now as the Fed is primed to resume easing policy.

“I don’t see a big drawdown in equity markets,” Haghbin said. “Anytime you have an accommodative Fed, if you look at history after the first rate cuts, markets tend to do pretty well.”

The house view at AllianceBernstein echoes this sentiment.

“We think that opting to stay on the sidelines simply because markets are reaching new highs could be a missed opportunity,” the firm said in the report. “Even though it’s natural to feel cautious when markets hit record levels, history suggests that there is still return potential to be tapped.”