Samsung (005930 KS) and SK Hynix (000660 KS) are reportedly expected to increase the share of 8-high products in their shipments of HBM4 to Nvidia (NVDA); sources suggest the plan to increase supply to Nvidia will begin in H2'26, ZDnet Korea reports

HBM supply planning of this kind has followed a familiar sequence through successive generations: customers qualify stacks per supplier, allocation is negotiated well ahead of volume, and the mix between lower and higher layer-count parts shifts as yields on the taller stacks mature. An expected tilt toward 8-high in HBM4 shipments to Nvidia reads as the standard early-cycle pattern, where the more manufacturable configuration carries initial volume before 12-high and beyond take over as qualification broadens. The fact that both Korean suppliers are reportedly planning the same shift from H2'26 suggests a customer-driven specification rather than one vendor's yield position, which in past cycles has been the more durable signal. The distinction worth drawing is between share of shipments and absolute volume: a higher 8-high mix can coincide with either rising or flat total bits depending on platform demand, and supplier read-throughs diverge accordingly. Follow-ons are formal qualification announcements, any commentary from the customer side on stack configuration for the next accelerator generation, and capex language on TSV capacity from both suppliers. As a single-outlet source story on shipment mix rather than a confirmed order, the signal is directional on technology ramp timing.