U.S. Treasury Buybacks Shock Quant Funds, Momentum Strategy Posts Worst Single Day in Two Years
Nashnova编辑部
The US Treasury announced it would at least double long-bond buybacks to stabilize the debt market; the same day Moderna nearly tripled in price. Quant hedge funds posted their worst single day in over two years as momentum strategies broke down in the violent rotation.
What exactly happened?
The US Treasury said it would at least double the size of its long-dated bond buybacks to calm the debt market. On the same day, Moderna surged nearly 200% after reporting successful skin-cancer vaccine trial results.
Both events hit at once, triggering sharp sector rotation — recent winners plunged, recent losers spiked. Momentum strategies — quant models that buy rising stocks and sell falling ones — were on the wrong side of every move.
This means → the funds didn't pick bad stocks. The market pattern their models rely on temporarily stopped working.
How bad were the losses?
According to a Goldman Sachs memo, systematic long-short hedge funds fell 1.4% on Wednesday; the firm's "global momentum" index deviated significantly from historical norms.
Morgan Stanley flagged that its "pure momentum" index dropped more than 4% in a single day — a first in at least five years — while the S&P 500 closed higher.
In plain terms = the broad market rose, yet quant funds lost money. The problem was not market direction — it was a sudden flip in the market's internal structure.
Was this an isolated event?
No. In the preceding weeks, a sustained selloff in AI-linked stocks had already caught Wall Street off guard, with multiple hedge funds posting monthly losses.
The most prominent casualty was the highly leveraged AI-themed fund Situational Awareness, which was ultimately forced to sell most of its public equity holdings to Citadel at a steep discount.
Prominent market-maker Jane Street also booked roughly $15 billion in losses last month from bets on Situational Awareness and related AI stocks.
This reflects a pattern: pressure on quant and AI-themed strategies has been continuous and compounding over the past month. Wednesday was just the day it all surfaced at once.
What are fund managers saying?
One hedge-fund manager: "Volatility is extreme — options market-makers are losing on both sides." Strategies that work one day almost certainly fail the next.
A portfolio manager at a large asset manager warned: "You don't need many 'Moderna-type' moves before risk officers start getting nervous."
A senior quant-fund executive used an earthquake analogy: "A magnitude-seven quake is always followed by aftershocks." Market participants are actively cutting exposure.
Could this become another "factor winter"?
Despite the single-day rout, Goldman's memo shows systematic long-short funds are still up 1.7% month-to-date — painful, but not fatal.
Yet the industry has a precedent: around 2018, factor strategies — value, growth, and other quant stock-selection signals — stopped working for years, a period the industry calls "factor winter."
This means → the real question is not "how much did they lose on Wednesday" but whether this violent rotation persists for months. If it does, the quant industry may face another round of systemic stress.
Content is for reference only, not financial advice.