The demand side rose and the supply chokepoint broke — hyperscalers gained on cooler CPI while the memory-and-optical layer cratered, Applied Optoelectronics down 13% and SK hynix off 11.5% in Seoul.

June CPI cooled to a headline −0.4% month-on-month and reopened the megacap demand trade: Alphabet (GOOGL) led the vertical's quotable names at +3.2% to $370.92, with Microsoft (MSFT) +2.8% to $395.63, Amazon (AMZN) +3.0% and Meta +3.1% — the hyperscaler buyers of compute. But the leadership was demand-side only. The supply chokepoint this vertical actually maps — memory, and the optical interconnect that has to move it — went the other way, and hard.

The laggard was Applied Optoelectronics (AAOI), down 13.0% to $109.09, the 800G/1.6T datacenter-transceiver name, on no company news — a high-beta unwind of the AI-optics trade that also took Lumentum (LITE) −7.7% to $752 at the same interconnect chokepoint. The memory tier drove the whole move: SK hynix (000660.KS) fell 11.5% to ₩1,842,000 in Seoul's latest session, deepening the HBM4-timing scare after a Korean brokerage cut its Q2 estimate below consensus, with Micron (MU) −8.0% to $904.28 following on the US tape and the silicon-wafer suppliers softening alongside them.

The split was the entire story. The SerDes-substrate-optical-memory plumbing sold off while the compute-demand proxies and the power-and-cooling layer held: Vertiv (VRT) +0.3%, Broadcom (AVGO) +1.3% to $394.28, Constellation (CEG) +0.7%, and ASML +2.2% to $1,815 into its print. CoreWeave (CRWV) gave back 3.5% to $77.12 as the neocloud demand proxy, and Intel −4.4% sat with the memory names. The structural tell holds: when the AI tape de-risks, the beta concentrates in the HBM-and-interconnect bottleneck, not in the end demand — the market keeps buying the picks-and-shovels story more violently than the buyers of the picks.

The reads now come print by print. ASML and TSMC both report today (July 16) — leading-edge tools and foundry demand. GE Vernova lands July 22; Intel, Besi and Samsung on July 23; Amkor July 27; Alphabet and Microsoft on July 28. The number the complex is bracing for is SK hynix's Q2 on July 29 — HBM4 pricing and shipment timing, the single input that decides whether this week's memory tax was a repricing or the start of a cycle.