At some point on Friday, a number ticked across trading screens and briefly rewrote corporate history: $4.88tn. That figure, Apple's market capitalisation by the close, was just enough to push Nvidia — whose $4.86tn valuation still dwarfs most national economies — into second place for the first time since April of last year.

The proximate cause was a 3.5% fall in Nvidia's share price, but the underlying story is more structural than a single session's jitters. Nvidia had entered rarefied air in October, becoming the first company ever to breach the $5tn threshold, a milestone powered almost entirely by insatiable demand for its graphics processors — the silicon backbone of the generative AI build-out. That run had kept it at the summit for the better part of a year.

Apple, by contrast, had been widely characterised as a laggard: a hardware company without a credible large-language model, watching rivals pour tens of billions into AI infrastructure. "Apple was seen as a laggard in the AI race because it wasn't spending to develop models, but now sentiment has changed," said Toni Meadows, head of investment at BRI Wealth Management. Last month's overhaul of Siri — long delayed and closely watched — appears to have shifted that perception enough to matter in market-cap arithmetic. The ranking shift also reflects a broader reallocation of investor attention across the semiconductor landscape.

Memory chipmakers, once considered unglamorous suppliers, have emerged as unexpected beneficiaries: South Korea's SK Hynix listed on the Nasdaq earlier this month, while Micron crossed the $1tn market-value mark in May as analysts reassessed memory's role in AI infrastructure. The AI trade, it turns out, is far wider than a single company's order book. Whether Apple can hold the position is genuinely uncertain.