Memory — SK hynix's 80% margin sends the Kospi +6.6% through 6,000; Fed and three mega-cap prints tonight
Tuesday extended the bounce and sharpened its message. The S&P 500 rose 0.6% to 7,722.60, the Nasdaq-100 gained 1.3%, and the VIX eased 4.7% to 17.5 — but the leadership was unmistakably the collection side of the AI trade. Celestica, Monday evening's +17% after-hours star, held almost all of it and closed +11.9% at 276.07; Amkor added 8.5%, Cadence 6.5% to 343.08. The optics-and-networking cohort ran again — Coherent +6.4%, Lumentum +5.9%, Fabrinet +5.5% — and the neoclouds outdid them all: Nebius +11.2%, CoreWeave +7.9%. Chip ETFs gained 3.0–4.7% across the complex while software barely moved and cloud slipped.
Two of the hardest-hit corners of the AI build-out have drawn the same shape on the chart. HBM Memory and High-Speed Interconnects both bottomed on 29 July, rallied, sold off by about a third into October, and then turned again on 22–23 October at almost the same level as in July. Memory held 7.6% above its July low, interconnects 2.9% above. That's a double bottom: two lows at a similar price, with buyers stepping in at the same place twice. Meanwhile, two other sectors never broke. EDA & Chip IP is flat on the month while our Rubin Build-Out index lost about 13%, and the chip designers set an all-time high as recently as 6 October. Beaten-down sectors finding a floor while the leaders hold their ground is what a tradable bottom in the whole index looks like. The Rubin index itself stopped just 0.2% under its July low. Breadth hasn't turned yet, and the levels that decide it are below.