Yesterday wiped out a lot of froth in AI hardware. Vertiv -17%. Nebius -13%. CoreWeave -10%. Micron -10%. Four different companies, four different reasons to own them, and the market sold all of them together anyway.

That’s the tell. When everything in a sector moves as one trade, valuation discipline has left the building. That makes the sell-off a good moment to separate the names with real earnings underneath them from the names running on a story.

The case for Micron (undervalued)

Micron trades at 18.5x trailing earnings and roughly 9x sales, cheap for a company that just posted 167% revenue growth and 693% earnings growth in a single quarter. Its PEG ratio is close to zero, meaning the stock price has barely caught up to the earnings growth already in motion.

Why the gap? Micron has spent two decades being priced as a boom-bust commodity chipmaker. The market still trades it on that muscle memory. But this cycle is different: HBM (high-bandwidth memory) for AI accelerators is sold out years in advance, DRAM and NAND are both in genuine supply shortage, and Micron is one of only three companies on earth that can make this memory at scale. That’s real pricing power in a historically cyclical business, and the stock still isn’t fully paying for it. Wednesday’s dip came from sector-wide contagion, unrelated to Micron’s own numbers.

The case against Nebius and Sandisk (overvalued)

Nebius is the clearest example of a story stock. It trades at 43x trailing sales on $878M of actual revenue, against a market cap north of $37B, pricing in flawless execution of its Microsoft computer deal for years to come. That’s not a valuation, it’s a bet on a single contract never wobbling.

Sandisk is the more painful lesson. It rallied over 500% this year on a real NAND shortage narrative, ran up to a $2,335 all-time high, then dropped double digits three sessions in a row. The underlying shortage story is genuine, but a $150B market cap on a spun-off NAND business had priced in a level of perfection that was always going to crack the moment sentiment turned. This is what happens when a real trend gets a speculative multiple bolted onto it.

Two more that deserve scrutiny

Vertiv, the AI data-center power and cooling play, trades at 50x trailing earnings and 7.5x sales. The backlog is real, but the stock’s -17% day shows how little room there was for anything less than perfect.
CoreWeave, still unprofitable, carries roughly $35B in debt against $2.3B of cash, a debt-to-equity ratio over 7x. Its price-to-sales multiple (5.3x) looks tame next to Nebius, but that’s masking real balance-sheet risk.

The pattern underneath all of this

The overvalued names all share one trait: their price depends on a narrative continuing uninterrupted, a contract renewing, a backlog converting, a shortage persisting, a loss turning to profit on schedule. The undervalued name, Micron, is priced on a narrative that already happened: memory is structurally short, and the earnings are already showing up in the reported numbers, not just the investor deck.

That’s the real split in hardware right now, cash flow versus story rather than good chips versus bad ones. When you can buy the cash flow at 18x earnings while the story is trading at 43x sales, that’s not a hard call.

Not investment advice. Do your own research before acting on any of this. Figures as of market close, July 29, 2026.

#Semiconductors  #AIInfrastructure  #Micron