HBM helps explain why the memory upcycle has been so strong.
Because it absorbs production capacity, AI demand lifts prices across the whole DRAM market, not just at the high end, which supports earnings at SK Hynix, Samsung and Micron and weighs on margins for PC, phone and server makers that buy memory
The concentration of supply makes the Kospi and the wider Korean market unusually sensitive to AI spending, and changes in HBM market share between SK Hynix and Samsung can move both stocks sharply. The main risk is the cycle turning: if new capacity and three-way competition in HBM4 catch up with demand, pricing power could fade quickly, as it has in past memory cycles. — Earlier, stunning results: SK Hynix Q3 operating profit beats at 83tn won, unveils 100tn won shareholder payout plan — HBM is the memory that keeps AI chips fed with data, and because it eats so much production capacity, it is pushing up prices for nearly every memory chip in the world. Summary: HBM stacks thin DRAM dies vertically and places them right next to the processor, delivering much higher bandwidth with less power.
AI chips are often limited by how fast they can be fed data, so every leading AI accelerator, including Nvidia’s GPUs, uses HBM. HBM uses around three times the wafer capacity per bit of standard DRAM, by industry estimates, so shifting production to it squeezes supply of ordinary memory and lifts prices. Only SK Hynix, Samsung and Micron make it at scale.