Key Highlights

● The VIX jumped 2.35 points to close at 19.03 from about 16.68 on Wednesday.

● The VVIX, a gauge of expected swings in the VIX, stood at 107.9.

● Treasuries rallied, and the 10-year yield fell under a key level.

● The Dow Jones Industrial Average edged up 11.89 points to 52,867.98.

The Cboe Volatility Index, known as the VIX, jumped 2.35 points to close at 19.03 on Thursday, October 22, according to market data. Another tally put the close at 19.04. The gauge had ended Wednesday at about 16.68.

The surge came as artificial-intelligence and chip stocks tumbled. The Nasdaq Composite sank 694.00 points to 26,008.86, its steepest drop since June 5, and the S&P 500 fell 93.74 points to 7,663.43, its worst session since July.

What the VIX measures

The VIX tracks the prices traders pay for S&P 500 options, translating them into an estimate of how much the index is expected to swing over the next 30 days. When investors scramble for protection against falling prices, options get more expensive and the VIX rises. That is why it is often called Wall Street's fear gauge.

A reading in the high teens is not extreme by historical standards, but the size of Thursday's jump signaled a clear shift in mood after a period of calm. The US market had hit a record high earlier in October.

What spooked traders

The trigger was a growing worry about the cost of the AI build-out. Meta Platforms (NASDAQ:META) reported after Wednesday's close that it expects 2026 capital spending of $135 billion to $145 billion and that its free cash flow turned negative. Its shares fell to $648.85, their worst day since July.

Lam Research (NASDAQ:LRCX) warned that supply-chain constraints would linger, and the Philadelphia Semiconductor Index suffered its biggest one-day drop since June 23. Nvidia (NASDAQ:NVDA) slid to $212.21 after CEO Jensen Huang said that "the demand of the capital is much greater than the availability of the capital." Bank traders said Huang's comments spooked markets.

"Investors are starting to realize that there are some holes in the AI story," one strategist said.

Nervous positioning beneath the surface

Other gauges of anxiety were also in focus. The VVIX, which measures expected swings in the VIX itself, stood at 107.9.

Sentiment had already been fragile. A weekly survey of individual investors showed bears outnumbering bulls. One bank said clients pulled a record $14.8 billion from single stocks, and another bank's data showed hedge funds' short-to-buy ratio at about five to one.

A sentiment watcher noted that the VIX put/call ratio stood at a low 0.18 on Wednesday, and wrote on Thursday: "Maybe we'll finally get a change in sentiment."

Broader market held up better

Despite the jump in the VIX, the selloff was narrow. About two of every three S&P 500 stocks rose, according to market reports, as investors moved into consumer staples, health care and utilities. The Dow Jones Industrial Average edged up 11.89 points to 52,867.98.

Other havens drew buyers too. Treasuries rallied, sending the 10-year yield back below a closely watched threshold for the first time since September 22. Gold, however, fell to its lowest in more than two months, while bitcoin dropped to around $81,200.

Some investors saw an opportunity. "Buying the dip here has [a] pretty good record of working," one commentator said.

A Dense Calendar for Volatility

The VIX will be sensitive to a busy calendar. Friday brings S&P Global purchasing managers' surveys and the final University of Michigan sentiment reading. Next week, the Federal Reserve announces its decision on October 28, the same day Microsoft (NASDAQ:MSFT) and Alphabet (NASDAQ:GOOGL) report, and GDP, PCE inflation and Amazon (NASDAQ:AMZN)'s results arrive on October 29. Oil, with Brent at $113.17, its highest since May 4, is another wild card for volatility.