SpaceX CEO Elon Musk attends a press briefing held by President Donald Trump with AI executives following a meeting on artificial intelligence, outside the West Wing of the White House in Washington, Sept. 29, 2026.

Finn Gomez | Getty Images

Shares of major neocloud stocks fell on Monday after Elon Musk said that more than 200 companies in the sector could collapse.

Nebius , CoreWeave and Iren all dropped more than 4% in early premarket trading, adding pressure to a sector already facing investor concerns about debt-fueled expansion and whether the large AI infrastructure buildout will generate returns. However, these stocks have since pared some of the losses.…