Traders betting against US stocks have gotten increasingly aggressive, and the numbers are starting to look historically extreme. Median short interest across S&P 500 constituents has climbed to roughly 3.7%, a level not seen in 11 years, according to data from Global Markets Investor.
The numbers across indexes tell the same story
The Nasdaq 100 is showing median short interest of approximately 2.7%, its highest reading in six years. But the real standout is the Russell 2000, where median short interest has pushed near 5.0%, a 15-year peak. Small caps, which tend to be more volatile and harder to short profitably, are attracting bearish bets at a pace that hasn’t been matched since the post-financial-crisis era.
The acceleration has been notable since mid-2024, with the pace of new short positioning picking up further into 2026.
What a short squeeze actually looks like
