Moody's Analytics chief economist Mark Zandi warned that a sudden White House crackdown on Anthropic‘s frontier AI models highlights a hidden "threat" capable of derailing the broader stock market and economy, clashing directly with Elon Musk‘s Space Exploration Technologies Corp. (NASDAQ:SPCX) IPO on the same day. Zandi took to X to warn that forcing Anthropic to pull its frontier models poses a “massive threat to that optimism, and by extension, the stock market and economy.” Citing urgent national security concerns, the Donald Trump administration slapped strict export controls on Anthropic's newly released Mythos 5 and Fable 5 large language models (LLMs), forcing the $965 billion startup to disable access for all non-U.S. citizens overnight. The sudden intervention reportedly followed warnings from Amazon.com Inc. CEO Andy Jassy, after researchers found the advanced models could be manipulated to assist in sophisticated cyberattacks. The regulatory shockwave stood in stark contrast to the historic public debut of SPCX on the exact same day, which Zandi noted became “the largest in history, by 3x.” SpaceX shares opened at $150.00 apiece, an 11.1% premium to the IPO price of $135, and closed its regular trading session 19.3% higher at $160.95, pushing its overall market valuation past the $2 trillion mark.