The trillion-dollar market cap club is starting to get crowded.
What's happening: Microsoft is now worth a smidge more than Apple, making the Satya Nadella-led cloud software giant the world's most valuable company. Both companies are worth about $2.5 trillion.
Google owner Alphabet is worth just a touch less than $2 trillion, while Amazon is valued at $1.7 trillion. And don't forget (as if we could) Tesla: Elon Musk's electric car giant recently passed the $1 trillion mark and has since surged to a market cap of about $1.25 trillion.
These five companies are now collectively worth almost $10 trillion. That's nearly a quarter of the combined $41.8 trillion market cap of the entire S&P 500.
It's possible that the S&P 500 could have six companies worth at least $1 trillion at the same time if Meta Platforms, the social media giant formerly known as Facebook, continues to rebound. Meta now has a market valuation of about $930 billion.
But given the continued strength in tech, it's altogether possible that all six of these companies could soon be worth at least $2 trillion, if not more. After all, Microsoft and Apple are knocking on the door of $3 trillion.
And other techs, such as chip leader Nvidia and China's Tencent are moving closer to the trillion dollar market valuation mark.
Step back: It seems almost unfathomable that so many companies could be worth this much. But earnings growth for many of the top techs continues to be strong, and that is pushing prices higher.
Still, the insatiable investor appetite for trillion-dollar techs reminds some market analysts of the Nasdaq froth of the 1990s and early 2000. It could be a warning sign.
"Tesla's rally is reminiscent of Cisco's move in 2000, a move that marked the bubble top in 2000," said Mike O'Rourke, chief market strategist with JonesTrading, in a report this month.
O'Rourke pointed out that Cisco shares soared about 50% in the first three months of 2000 and analysts at Credit Suisse predicted that Cisco would be the world's first trillion-dollar company.
It didn't happen. Cisco, which was worth about $550 billion at the height of tech stock mania two decades ago, is now valued at about $240 billion. Intel, another tech stock leader of the late '90s, has struggled in the past few years and is nowhere close to its 2000 peak valuation.
It's proof that becoming a market leader may be easier than staying a market leader. There is no guarantee that the likes of Microsoft, Apple, Amazon, Alphabet and even Tesla will stay at the top.
Newer companies and technologies may come along that could make the list of the world's most valuable firms look a lot different in the early 2040s than in 2021.
