Tech just had a crisis-sized day — the kind that came in 2000, 2008, and 2020: Chart of the Day

The S&P 500 ( ^GSPC ) fell more than 4% Thursday, and tech fell nearly twice as far. The Technology Select Sector SPDR Fund ( XLK ) dropped 8%, its worst day since March 16, 2020, the worst day of the pandemic crash.

The AI trade took the brunt of Thursday's sell-off . Nvidia ( NVDA ) and Broadcom ( AVGO ) fell about 9% to 10%, and the PHLX Semiconductor Index ( ^SOX ) lost 12%.

The S&P 500 tech sector is about 17% below its Oct. 6 record after 22 sessions. About 4% more would mean a bear market , and doing it within two sessions would make it the fastest since 2020, by Yahoo Finance calculations. Only the dot-com and pandemic crashes moved quicker.

XLK's only worse days came in March 2020 and the 2008 financial crisis. Since 1989, the sector has had six earlier drops of 6% or more while near a record. Five blew over fast, with tech falling another 3% to 14% and returning to a record within two to seven months.

The sixth was April 12, 2000. Tech fell another 78% and didn't see a record again until 2017.

Those five came from outside tech, from a failed airline buyout in 1989 to the Asian financial crisis , the Long-Term Capital Management blowup, and the pandemic and tariffs, and most got fast relief from the Fed or Washington. In 2000, the problem was tech itself. This time has a little of both, a political trigger and a worry about tech's own AI spending .

Market breadth is one way Thursday looked more like 2000. On the five crisis days that ended in quick recoveries, at least 8 in 10 S&P 500 stocks fell along with tech. On April 12, 2000, most of its stocks rose even as the index fell about 2%. Thursday landed in between. About 85% of S&P 500 stocks fell, but 74% held up better than the index, according to a Yahoo Finance analysis of Norgate Data.

The Chart Report wrote Thursday that semiconductors "are flashing the same momentum reversal that marked their 2000 top."

While the chart pattern looks familiar, corporate earnings say otherwise. In the year before the March 2000 peak, tech stocks doubled while forward earnings estimates rose 23%. In the year before October's record, prices rose 32%, and estimates jumped 73%. Tech trades at about 24 times forward earnings, versus 62 in March 2000.

Size is where 2026 can hurt like 2000. Tech hit a record 39% of the S&P 500 in October, above its 35% peak in 2000. When tech goes, the index goes with it.

Richard Bernstein, global head of macro and customized investing at Janus Henderson Investors, said the danger is in how momentum ends.