Markets tumbled around the world Tuesday as renewed doubts about sky-high valuations appeared to take hold of investors in some of the largest AI, chip and memory stocks.

Limited time: Save 25% on NBC News subscription

Get exclusive reporting, live Q&As and ad-free reading.

The deepening sell-off in technology stocks was led by artificial intelligence and chip stocks, starting overnight with two of South Korea’s largest companies.

Market sentiment was also hurt by Elon Musk’s SpaceX, which has slid for days after a blistering June 12 debut on the U.S. market. Shares fell as low as $147 earlier Tuesday before they ended the day higher by 1.7%.

The latest tumult was caused in part by worries over the sustainability of stunning surges in…