Markets tumbled globally on Tuesday, as renewed doubts about sky-high valuations appeared to take hold of shares in some of the largest AI, chip and memory stocks.This deepening sell-off of leading technology stocks was led by Elon Musk’s SpaceX, which has slid for days after a blistering debut on the U.S. market. This latest tumult is caused in part by worries that rising inflation stemming from the Iran war and the closure of the Strait of Hormuz could lead to higher interest rates and more expensive borrowing for the ever-expanding global AI infrastructure buildout.04:05Nasdaq 100 futures plunged 2.8%, which would put the index on track to erase more than $1 trillion in market value if the drop holds through the end of the day. S&P 500 futures slid 1.6% and Dow futures dropped nearly 300 points. Even the Russell 2000, which tracks small and mid-cap stocks that often avoid the volatility in major tech stocks, fell 1.4%.In pre-market trading, shares of Intel, Marvell, Western Digital and AMD plunged more than 5%. Broadcom, Nvidia, Tesla and Alphabet fell more than 3%. Bond yields were mixed, with shorter-term U.S. Treasury yields rising slightly and longer-dated yields — such as the 10-year — falling slightly.SpaceX shares, which are set for their fourth straight down session, tumbled another 4% in pre-market trading to about $147, below the $150 where the stock opened at in its stock market debut. However, SpaceX shares remain above its $135 IPO offering price. Recent selling in SpaceX shares has wiped out more than $900 billion in value from the company’s peak of $225 per share, which it hit one week ago. On Monday alone, shares fell nearly 17%, erasing $400 billion in value — the second largest one-day wipeout for any stock on record, according to Bloomberg. Selling in SpaceX accelerated Monday after the company announced an “inaugural bond offering,” likely to be used in large part to fuel its AI ambitions. Bloomberg reported the company wanted to raise about $20 billion in the bond offering, which would be on top of the $85 billion it raised through its IPO just two weeks ago. Collectively, all of the so-called “magnificent seven” stocks — Alphabet, Amazon, Apple, Meta Platforms, Microsoft, Nvidia, and Tesla — were down in pre-market trading Tuesday, except for Microsoft which showed a brief gain. Nvidia and Tesla were set to be the worst affected. On Monday, Alphabet shares recorded their worst single day in a year after high-profile AI talent left the company. Shares continued the downward trajectory in early Tuesday trading, sliding another 2.3%. Major tech stocks also sold-off globally.In Korea, the country’s flagship Kospi index closed sharply lower by 10% after two of its most valuable companies, Samsung and SK Hynix, both slid more than 12%. However, the Kospi has been volatile this year and earlier in June the index plunged 8.2% and then recovered by the almost the same exact amount the following day.In Europe, the Stoxx 600 fell about 1%, while Germany’s flagship DAX index tumbled 1.3%. Semiconductor maker Infineon was the biggest decliner on the DAX, falling more than 5%.“Gravity strikes,” JPMorgan traders said in a note to clients earlier on Tuesday, referring to Asian indexes and U.S. and E.U. futures. In a separate note, JPMorgan traders said the selling could be some “anxiety” before memory maker Micron reports earnings on Wednesday afternoon. Dan Ives, head of tech research at Wedbush Securities, agreed. “With Micron set to report earnings this Wed there is some added nervousness on the important memory chip trade,” he wrote in a note.Micron shares were down 9% in early Tuesday trading.Still, shares of Micron are up more than 300% since the start of this year and more than 870% over the last 12 months. Likewise, Samsung shares remain higher by 160% this year and 412% over the last 12 months. SK Hynix shares are still holding onto a more than 800% gain over the last year.“In this market we will continue to go through a number of ‘gut check moments’ in the tech trade as the AI Revolution remains in the 3rd inning,” Ives also said. “This morning is just another one of those moments.”Meanwhile, oil prices dipped slightly lower after traders continued to digest the latest headlines surrounding talks to definitively end the war between the U.S. and Iran.While small amounts of traffic have passed through the Strait of Hormuz since the initial agreement was announced, including 15 tankers on Monday according to S&P Global, traders appear to remain concerned about resuming significantly higher flows. “A tentative U.S Iran truce has eased immediate oil supply concerns, triggering a $25–30/barrel decline in prices,” Société Générale said in a note to clients on Tuesday. “Despite this, the back end of the Brent curve remains elevated, with long-dated Brent still around $10/barrel above pre-war levels.” “A rapid return to normal is unlikely given logistical constraints, including mine clearance, routing bottlenecks, and Iranian transit frictions,” SocGen’s analysts added. “Recovery in Hormuz flows is therefore expected to be gradual rather than immediate.”