Momentum stocks are currently experiencing volatility at 4.0 times the level of the S&P 500, a record ratio that signals something unusual is happening beneath the surface of what looks like a functioning market. Nvidia, the AI chipmaker that has essentially become the poster child for momentum investing, sits at the center of this storm.
What the 4.0x ratio actually means
Three-week realized volatility measures how much a basket of stocks has actually moved over the past 15 trading days. Comparing that to the S&P 500’s own three-week volatility gives you a ratio. A ratio of 1.0 would mean momentum stocks are behaving roughly like the broader market. A ratio of 2.0 means they’re twice as jittery.
Momentum strategies buy what’s been going up and sell what’s been going down. When a handful of stocks, Nvidia chief among them, dominate the “going up” category, the entire momentum factor becomes a leveraged bet on those names.
Why this matters beyond equities
