Momentum rout hits quant funds as Treasuries stabilize and Moderna surges

Quant hedge funds had their worst day in over two years as the U.S. Treasury moved to double long‑term debt purchases to shore up the bond market, adding pressure to momentum strategies already shaken by an AI stock sell‑off. Goldman Sachs said its global momentum index was well outside historical norms, with systematic long‑short funds down about 1.4% at 1pm ET, and Morgan Stanley’s pure momentum index dropping more than 4% while the S&P 500 rose. Moderna surged nearly threefold after positive trial results for an experimental skin‑cancer therapy, underscoring the day’s dramatic stock moves. Despite the setback, systematic long‑short funds were up about 1.7% for the month, and traders warn that volatility remains extreme, noting notable losses at Jane Street and the Situational Awareness fund as risk-off sentiment broadens.