Muddy Waters Founder Goes Short: If AI Continues to Replace White-Collar Workers, US Stock 401K System May Collapse

Well-known short-selling firm Muddy Waters founder Carson Block warns that artificial intelligence is fundamentally changing his market outlook, shifting his overall view from bullish to bearish. He predicts that within the next three years, 15% of knowledge workers in the U.S. will lose their jobs, potentially triggering a systemic shock to the stock market due to rising unemployment.

According to Bloomberg on Thursday, Block stated at the Future Proof Wealth Management Conference in Miami Beach that just a month ago, he was fully optimistic about the S&P 500 and the overall economy, but now his outlook has “done a 180.” This sudden reversal came quite unexpectedly—last November, he publicly expressed a preference for going long rather than short on the U.S. market and disclosed several unconventional long positions.

Block’s main concern is that AI-driven employment disruptions will transmit through the labor market into financial markets. Once unemployment rises and reduces inflows into retirement accounts like 401(k)s, or even forces unemployed workers to dip into their savings early, the stock market could face sustained capital outflows, leaving “no one to catch this falling knife.”

Legal, accounting, and financial support roles are first in line

Block expects that AI-driven job displacement will initially impact fields such as law, accounting, tax consulting, and financial support, especially targeting entry-level and administrative positions. In the hedge fund industry, he believes many operational and back-office functions, including IT jobs, could be replaced by cheaper, more efficient automation systems.

He notes that profitable large institutions may still continue hiring junior analysts out of habit, but companies with thinner profit margins will quickly turn to automation. This divergence means that employment pressures will first manifest in small and medium-sized enterprises and low-margin industries.

Block’s assessment aligns with current market anxiety—investors are increasingly worried whether the hundreds of billions of dollars poured into AI infrastructure will generate sufficient returns or merely accelerate corporate disruption and large-scale white-collar job losses.

Shorting credit spreads, seeking convexity opportunities

Despite the overall bearish shift, Block says his team is already looking for structural opportunities in the market. Currently, Muddy Waters has positioned itself to bet on widening credit spreads and is trying to profit from liquidity mismatches in some exchange-traded funds.

“I think credit spreads are ridiculously tight right now, and credit volatility is ridiculously low,” he said. “In my view, you need convexity, and there are many ways to position yourself while controlling maximum losses.”

This strategy reflects Block’s view that current market pricing is overly optimistic—he believes investors, long accustomed to low interest rates, have become excessively tolerant of risk, enabling aggressive corporate behaviors.

Gray areas proliferate, but markets no longer care

Block also discussed the difficulties his core short-selling business faces. He believes that years of loose monetary policy have not only inflated asset prices but also encouraged companies to adopt aggressive accounting and disclosure practices, creating a broad “gray area.”

However, market tolerance for such behavior is increasing. “My business is becoming harder and harder because unless something is extremely, extremely egregious, people just don’t care,” he said. This means that even with many companies potentially having issues, short-selling firms find it difficult to garner enough market resonance and returns.