Will Alphabet be the third-largest company in the world by market cap on May 31?

Prediction markets put the probability at 7%: Will Alphabet be the third-largest company in the world by market cap on May 31. Currently, markets see this as unlikely (7% YES). Google and Blackstone Join Forces to Topple Nvidia’s AI Cloud Dominance - Barron's.

What’s Happening

Alphabet shares approached a $5 trillion market capitalization milestone in mid-May, fueled by a strategic partnership announced on May 19, 2026 with Blackstone to expand AI cloud infrastructure and challenge Nvidia's dominance in the segment. The Google parent currently sits within the top-five global rankings alongside Nvidia, Apple, Microsoft, and Amazon, with the latter pulling back roughly 3% last week after approaching the $3 trillion threshold. The question of whether Alphabet will be the third-largest company in the world by market cap on May 31 hinges on a narrow spread separating the top contenders, with Forbes citing a forward P/E ratio of 28x against a five-year historical average of 21x, reflecting a 35% AI-driven premium. [Barron's, May 19]

Sentiment turned more cautious on May 19 after Alphabet's earnings disclosures during the Google I/O event fell short of Wall Street consensus, sending shares lower in intraday trading. The miss complicates the path to overtaking the third-place slot, particularly as Pershing Square disclosed on May 15 that Bill Ackman's fund had slashed its Alphabet position during Q1 2026 while adding Microsoft as a core holding — a rotation that mirrors broader institutional repositioning across the megacap-tech complex. Historically, ranking shifts among the top-five market-cap leaders have occurred within trading windows of 72 hours or less when earnings catalysts coincide with macro repricing, as seen in the August 2024 Nvidia-Apple swap. [CNBC, May 19]

The probability that Alphabet captures the third-largest company in the world by market cap on May 31 depends on relative performance against Nvidia, Apple, and Microsoft across the final eight trading sessions of May, with Forbes noting Alphabet's anticipated 2026 EPS of $14.22 underwriting the bull case for further multiple expansion. Investor's Business Daily reported that Amazon rallied 27% from April through an intraday record of 278.56 on May 5, intensifying competition for the lower rungs of the trillion-dollar club. With AI capex narratives driving differential repricing and Treasury yield-curve dynamics influencing duration-sensitive megacap multiples, traders will watch end-of-month rebalancing flows and any guidance revisions tied to the Blackstone partnership rollout. [Investor's Business Daily, May 18]

Traded on Polymarket — $58K Volume

Lower-volume market on Polymarket ($58K). Wider spreads expected — enter with limit orders and be aware of slippage risk. Currently 19c YES.