The Nasdaq-100's worst day since March 2020. Was it bigger than COVID?

Thursday brought record point drops for the S&P 500 and the Nasdaq indexes, but in percent the day was far smaller than the worst of March 2020. The exception is chips, where the main index is already further below its June high than it fell during COVID. By PYE Markets (@pyemarkets).

Thursday 5 November was one of the sharpest sessions in years, and the COVID comparison arrived quickly. On closing prices, the answer depends on the measure. In points, it was the largest one-day drop on record for the S&P 500, the Nasdaq-100 and the Nasdaq Composite. In percent, it was well short of the worst of March 2020. In chip stocks, the comparison holds up: the fall from the June high is now as deep as the COVID fall, or deeper.

The day, against the worst day of COVID

Each line shows Thursday's fall, then the fall on 16 March 2020.

- S&P 500: −4.36% (−335 points), against −11.98% - Nasdaq-100: −6.36% (−1,807 points), against −12.19% - Nasdaq Composite: −5.52% (−1,422 points), against −12.32% - Dow Jones Industrial Average: −3.44% (−1,833 points), against −12.93% - PHLX Semiconductor index: −12.25% (−1,258 points), against −15.90%

For the Nasdaq-100 and the semiconductor index, it was the worst day in percent since 16 March 2020. For the S&P 500, the Dow and the Nasdaq Composite, the last worse day was in April 2025.

Why the point records mislead

A point drop grows with the level of the index. The S&P 500's 335 points beat the 325 it lost on 16 March 2020, but that day it started from about a third of today's level. A repeat of that day's percentage from Wednesday's close would have been a fall of 921 points.

Ranked by percent, Thursday was the S&P 500's 43rd-worst session of 14,333 since 1970 in Yahoo Finance's data. Six of the 23 sessions in the 2020 fall were worse.

The two falls also differ in size so far. The S&P 500 closed 5.95% below its 6 October record, while the COVID fall reached 33.92%. The Nasdaq-100 is 14.71% below its record, against 28.03%. The Nasdaq Composite, at 11.90% below, is in what markets call a correction, a fall of at least 10%.

The Cboe VIX tells the same story. It jumped from 16.61 to 28.18, and it closed at 82.69 on 16 March 2020 and 52.33 on 8 April 2025.

Where the comparison holds: chips

The semiconductor index closed 38.43% below its 22 June high. Its fall in early 2020 reached 34.99%. The speed is the difference: this fall has taken 96 sessions, and that one took 20. SMH, a large chip ETF, gives a similar picture from a different basket, at 33.07% now against 33.62% then.

Thursday's losses were concentrated in the companies closest to AI spending:

- Memory and storage: Sandisk −22.26%, Micron −17.46%, Western Digital −17.35% - Chips and equipment: AMD −17.26%, Lam Research −16.36%, Applied Materials −13.58%, TSMC −10.78%, Broadcom −10.43%, Qualcomm −9.49%, Nvidia −9.26% - The largest AI spenders: Meta −3.96%, Microsoft −3.58%, Alphabet −2.20%, Amazon −2.19%

An equal-weighted S&P 500 fund (RSP) fell 2.89%, much less than the index itself, which shows how much of the fall came from the largest stocks. Selling did reach beyond them, though: the Russell 2000 of smaller companies fell 4.45%.

What the reports point to

The day followed a rally: on Wednesday the Dow rose 3.03%, its best day since April 2025, and the S&P 500 rose 1.58%. NBC News put Thursday's loss at $2.8 trillion of S&P 500 market value.

CNBC and NBC News link the reversal to the midterm results, which raised concern that building AI data centers will get harder. CNBC reports that voters sided against data centers in all but one of 41 local ballot measures, citing Ballotpedia and its own count. It also names rising interest rates, large capital needs and a disappointing forecast from Qualcomm. These are reported explanations, and a single day's fall rarely has one clean cause.

Ed Yardeni told NBC News: “I don’t think this is an AI bubble bursting.” That is one view, and the next few weeks will test it.

What we don't know

We are not publishing a figure for what usually happens after a day like this. Days this size cluster in a few crises, so the real sample is much smaller than a count suggests. One session also says little about whether this stays a fall in AI stocks or spreads further.

The next scheduled test is the US jobs report, due at 8:30 AM ET on Friday 6 November.

General market information, not investment advice. Index and stock figures are from Yahoo Finance daily closes through 5 November 2026; percentages and point changes are our arithmetic on those closes.

Checked before publishing: each of the 55 figures in this piece is tied to one of the 13 sources below, or marked as our own arithmetic. Sources accessed 5 Nov 2026. How we check

Sources

1. Yahoo Finance, S&P 500 (^GSPC) daily closes, accessed 5 Nov 2026 2. Yahoo Finance, Nasdaq-100 (^NDX) daily closes, accessed 5 Nov 2026 3. Yahoo Finance, Nasdaq Composite (^IXIC) daily closes, accessed 5 Nov 2026 4. Yahoo Finance, Dow Jones Industrial Average (^DJI) daily closes, accessed 5 Nov 2026 5. Yahoo Finance, PHLX Semiconductor index (^SOX) daily closes, accessed 5 Nov 2026 6. Yahoo Finance, Cboe VIX (^VIX) daily closes, accessed 5 Nov 2026 7. Yahoo Finance, VanEck Semiconductor ETF (SMH) daily closes, accessed 5 Nov 2026 8. Yahoo Finance, daily closes for the stocks named (NVDA as the example page), accessed 5 Nov 2026 9. Yahoo Finance, Invesco S&P 500 Equal Weight ETF (RSP) daily closes, accessed 5 Nov 2026 10. Yahoo Finance, Russell 2000 (^RUT) daily closes, accessed 5 Nov 2026 11. CNBC, chip stocks and the midterm results, accessed 5 Nov 2026 12. NBC News, stocks and the midterm results, accessed 5 Nov 2026 13. BLS news release schedule, Employment Situation date and time, accessed 5 Nov 2026