U.S. stocks finished mixed on Friday the 18th during a quadruple-witching session, when index futures, index options, single-stock futures and single-stock options expired simultaneously, lifting trading volume and intraday volatility. The Dow Jones Industrial Average fell 95.40 points, or 0.18%, to 51,682.64, snapping a two-session winning streak. The S&P 500 rose 12.74 points, or 0.17%, to 7,650.50, while the Nasdaq Composite gained 104.25 points, or 0.39%, to 26,522.55. The Philadelphia Semiconductor Index was the strongest major gauge, surging 322.20 points, or 2.78%, to 11,921.69 as memory stocks rallied. SanDisk jumped 10.99% to $1,791.82, Micron rose 3.92% to $1,015.80, Western Digital gained 4.13% to $441.36 and SK Hynix ADR advanced 2.46% to $187.50. Intel CEO Lip-Bu Tan said AI infrastructure expansion and memory demand showed no signs of cooling, and that memory prices had risen to five to seven times their previous levels. TSMC ADR rose 1.02% to $434.67, while Taiwan Index Futures' night session slipped 0.05% to 47,405, remaining above 47,000. Investors continued to assess the Federal Reserve's quarter-point rate hike to a 3.75%-4.00% target range, elevated Treasury yields and a rebound in oil prices. The session highlighted a rotation toward semiconductor and memory shares with strong earnings momentum rather than a broad-based advance across equities.