For years, Apple has ruled as the U.S. stock with the largest market cap. In August, Apple’s market cap rose above the $1 trillion level, becoming the first U.S. stock to reach that level. Last month, however, Apple’s stock tumbled on a disappointing outlook for the holiday season this quarter. Microsoft’s stock also fell during the selloff in tech stocks but held up relatively well.

According to Bloomberg, Apple’s market cap fell to $812 billion during intraday trading Monday, while Microsoft’s rose to $819 billion. “It most likely won’t be long until Microsoft is firmly entrenched again as No. 1 in the world,” Bloomberg’s Shira Ovide wrote. “Longer-term, Microsoft has continued to roll as the go-to shepherd for corporate clients anxiously navigating technology changes in their industries.”

Microsoft and Apple were bitter rivals for decades. The two companies emerged as leaders in the 1980s during the early days of the personal computer industry. Microsoft became a juggernaut among software makers, while Apple and other Silicon Valley companies fought for market share. Microsoft’s dominance in the PC software market gave it a market value that was larger than Apple’s for years.

In early 2010, Apple’s market cap surpassed that of Microsoft and remained above it for the next eight years, as consumers moved away from desktop computers in favor of smartphones and tablets. Apple introduced the iPhone in 2007 and the iPad in 2010. Since then, Microsoft has moved away from Windows software as an engine of revenue growth in favor of enterprise software, particularly cloud services like Azure.