SK hynix (000660.KS) — 2025Q4 FY2025 Earnings Call Analysis

58% Operating Margin with a Hard Capacity Ceiling

They hit record profits and net cash, but management is already talking about 'physical limitations in production space.'

Thesis: SK hynix has transitioned from a cyclical memory player to an AI bottleneck owner. While the street fears a capacity ceiling, the 20% DRAM ASP hike proves they have the hammer on pricing until the M15X capacity hits in 2026. The 69% EBITDA margin is a structural shift, not a spike.

Verdict: LONG — Conviction: HIGH

Catalyst: HBM4 volume ramps through 2026 with custom HBM discussions already underway.

Key Risk: TSMC CoWoS-L packaging constraints limiting HBM4 die utility.

The Tell: Management admitted physical limitations in production space while promising to maximize production within feasible limits, signaling they are redlining current fabs until 2026 infrastructure matures.

Friction Level: MODERATE_FRICTION — The sustainability of 58% margins given the upcoming KRW 12.2 trillion buyback and a 'considerable' 2026 CapEx spike during an AI inference shift.