US Stocks Mixed on Aug 12, 2026; AI Shares Surge, SK Hynix Up 9%, Nebius 34%, CoreWeave 19%
On August 12, 2026, US stocks closed mixed: the Dow fell 0.04%, the Nasdaq rose 0.54%, and the S&P 500 gained 0.26%. AI-related shares surged, with SK Hynix up over 9%, Nebius up over 34%, and CoreWeave up over 19%. Other gainers included Seagate (over 7%), SanDisk (over 5%), Micron (over 4%), Western Digital (over 3%), Applied Materials and Lam Research (each over 4%), KLA (over 3%), Lumentum (over 13%), Coherent (over 8%), and Corning (over 5%).
On Tuesday, August 12, 2026, US stocks closed mixed. The Dow Jones Industrial Average fell 0.04%, the Nasdaq Composite rose 0.54%, and the S&P 500 gained 0.26%. AI-related stocks were broadly active, with several names posting significant gains.
In the memory chip segment, SK Hynix rose over 9%, Seagate gained over 7%, SanDisk advanced over 5%, Micron Technology added over 4%, and Western Digital climbed over 3%. Among semiconductor equipment makers, Applied Materials and Lam Research each rose over 4%, while KLA gained over 3%. In the new-generation AI cloud services space, Nebius surged over 34% and CoreWeave jumped over 19%. In optical communications and photonics, Lumentum rose over 13%, Coherent gained over 8%, and Corning advanced over 5%.