The Nasdaq 100 fell 6.36% on Thursday, its worst day since 2020, as investors sold everything from memory and storage stocks to chip equipment makers and data-center suppliers. The Nasdaq Composite fell 5.52%, the S&P 500 dropped 4.35%, and the Dow lost 1,833 points. All three had their worst day since April 2025.A day after the Dow surged nearly 1,600 points, it gave back the entire gain and then some. The Russell 2000 fell 4.45%, and all 30 Dow stocks closed lower. The selling was most intense in the AI trade, but by the close it had spread well beyond it.Investors continued to weigh what the midterm results could mean for the pace of the AI data-center buildout. Treasury yields moved lower and gold caught a bid as stocks sold off. Lower yields can help growth stocks, but today they came alongside a broad move away from risk and offered little relief to tech.U.S. stock market closing levelsDow Jones Industrial Average −1,833.16 points (−3.44%) to 51,528.16S&P 500 −334.77 points (−4.35%) to 7,353.85Nasdaq Composite −1,421.52 points (−5.52%) to 24,315.00Russell 2000 −127.11 points (−4.45%) to 2,729.84Nasdaq 100 −1,807.36 points (−6.36%) to 26,629.81Every Dow stock fellNvidia led the Dow lower with a 9.26% decline. Cisco fell 7.62%, Goldman Sachs lost 6.44%, Caterpillar dropped 6.39%, and Honeywell fell 5.55%. Verizon (−0.04%) and Coca-Cola (−0.07%) came closest to finishing flat.The breadth numbers tell the same story. S&P 500 decliners outnumbered advancers 411 to 75. Across the Nasdaq, 2,822 stocks fell and 463 rose, a little more than six decliners for every advancer. On the NYSE Composite, the count was 1,512 down and 288 up.The AI and chip names that fell 10% or moreThe closing watchlist showed 22 individual stocks down at least 10%, plus the VanEck Semiconductor ETF. Sandisk led the declines, and the losses ran through nearly every part of the chip and data-center supply chain.Memory and storage — Sandisk −22.26%, Micron Technology −17.46%, Western Digital −17.35%.Chip designers and manufacturers — AMD −17.26%, Arm Holdings −13.08%, Taiwan Semiconductor −10.78%, Texas Instruments −10.70%, Broadcom −10.43%, Intel −10.33%, Monolithic Power Systems −10.28%.Networking, connectivity and optics — Astera Labs −19.62%, Lumentum −18.68%, Credo Technology −17.71%, Marvell Technology −16.43%, Coherent −12.98%, Arista Networks −10.82%.Semiconductor equipment and components — Lam Research −16.36%, Applied Materials −13.58%, SkyWater Technology −13.40%, KLA −13.35%.Data-center compute and power — Nebius Group −14.95%, Bloom Energy −16.41%.Semiconductor ETF — VanEck Semiconductor ETF (SMH) −11.21%.All seven Mag 7 stocks fall, led by Tesla and NvidiaThere was no green in the Magnificent Seven, but there was a big difference in how the stocks held up. Tesla fell 10.77% and Nvidia lost 9.26%. They were the only two to fall more than the S&P 500 (−4.35%), the Nasdaq Composite (−5.52%) and the Nasdaq 100 (−6.36%).Apple held up best, down 1.53%, followed by Amazon (−2.19%) and Alphabet (−2.20%). Microsoft and Meta also held up better than the three broader indices, although both fell more than the Dow (−3.44%).Tesla −10.77% to $343.69Nvidia −9.26% to $181.60Meta Platforms −3.96% to $605.08Microsoft −3.58% to $535.93Alphabet −2.20% to $282.57Amazon −2.19% to $260.21Apple −1.53% to $344.17On the next bounce, I’ll be watching Tesla and Nvidia. If buyers step in and those two can hold their gains, it would be an early sign that the selling pressure is easing in the hardest-hit megacaps.The YTD scorecard after the selloffThe YTD numbers put the selloff in perspective. SanDisk fell more than 20% on the day and was still up more than 200% for the year. Micron and AMD each fell about 17%, yet both held on to substantial YTD gains. Nvidia and Broadcom were already on the other side of the ledger by the end of the session. The selling hit the chip stocks hard, but the cushion going into the day varied considerably.The Magnificent 7 are split three up and four down. Apple leads the group at roughly +27% YTD, with Amazon and Microsoft still up double digits. Tesla is the weakest at about −24%. Outside tech, Target, Chevron, ExxonMobil and Coca-Cola are still sitting on sizable gains. Meanwhile, some of the deepest losses on the watchlist are in software, with Intuit down about 46% and Oracle off 41%.All five major U.S. indices are still positive for 2026 after the November 5 selloff. The Russell 2000 is the only one still up double digits, while the Nasdaq Composite has the smallest gain. AP NewsPrice returns through the November 5 close, measured from the December 31, 2025 close.The Nasdaq Composite went into the session up about 10.7% for the year and came out up just 4.6%. The S&P 500’s gain narrowed from about 12.3% to 7.4%. What traders should watch after a selloff like thisSellers have control heading into the next session. The first thing I’ll watch on a bounce is whether it can hold and whether more stocks participate. A few megacaps can lift an index early even while most stocks are still falling. If breadth improves and the chip stocks that led the decline start to hold their rebounds, buyers have more evidence that the selling is easing. If those stocks give back their gains and breadth stays weak, the burden remains on the buyers. This article was written by Greg Michalowski at investinglive.com.