Samsung makes about a third of the world’s DRAM—the memory inside virtually every phone, laptop, server, and data center on the planet. Together with its Korean rival SK Hynix, it controls roughly two-thirds of the global DRAM market and an even larger share of high-bandwidth memory (HBM), the specialized chips that AI systems cannot run without. Samsung and SK Hynix are two of only three companies that make HBM at all; the third being American semiconductor company Micron.

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When people talk about AI infrastructure, they tend to focus on Nvidia’s GPUs. But those GPUs are useless without the memory chips stacked alongside them, and Samsung’s three fabrication complexes in South Korea are among the most important pieces of the AI industrial boom. Samsung operates 12 fabrication lines, employs over 260,000 people worldwide, and is investing $73 billion in semiconductor capex and R&D this year alone, the largest single-year chip investment by any company in history.

That’s why it’ll be a shock to the system when on May 21, nearly 45,000 of Samsung’s unionized workers plan to walk off the job for 18 days. If that happens, it will be the largest work stoppage in the history of the semiconductor industry, at the single most important chokepoint in the AI supply chain. But unlike past labor disputes, AI hyperscalers won’t be able to absorb a supply disruption.

The strike

Last September, SK Hynix settled with its own union to allocate 10% of annual operating profit directly to employees as performance bonuses for the next decade, while removing caps on bonuses. Based on 2026 profit forecasts, that translates to average payouts of $460,000-$477,000 per worker this year across SK Hynix’s 35,000 staff, with projections approaching $900,000 per person next year. This is nothing new for SK Hynix: it already paid profit-sharing bonuses averaging about $95,000 per employee this past February.

Now, Samsung’s unions are requesting 15% of operating profit be allocated to a bonus pool, removal of the current cap that limits bonuses to 50% of base salary, and a 7% wage hike. Management countered with roughly 13% of operating profit, but only as a one-time payment for 2026, and didn’t commit to permanent structural changes.

The competitive pressure has already become an issue for Samsung’s talent. Union chairman Choi Seung-ho said roughly 200 Samsung employees have left for SK Hynix over the past four months. In 2024, Samsung paid no performance bonuses at all after the chip unit posted operating losses throughout the memory downturn. And while the turnaround has been staggering, with Q1 2026 operating profit increasing nearly eightfold to a record, the workers received none of the payout.

After a 17-hour negotiation session at the National Labor Relations Commission on May 13 failed to produce a deal, the NLRC struggled to find a compromise. The commission initially proposed roughly 40 trillion won ($26.7 billion) in total bonus payouts, which the union rejected. Samsung then sent a letter proposing further direct dialogue, and the union accepted only if co-CEO Jun Young-hyun personally presents concrete proposals on key issues. No deal has been reached yet.

In April, a one-day labor walkout forecasted what an extended strike could do. Foundry output reportedly dropped 58% and memory fabrication fell 18% during that affected shift. Samsung believes a full shutdown could occur for the strike’s planned 18-day span with nearly 45,000 union members expected to participate. Should such a thing happen, industry estimates put potential losses at 30 trillion-100 trillion won. Samsung has begun “warm-down” procedures, scaling back wafer inputs, as halting chip fabrication mid-process means scrapping wafers that cost $20,000 each.

The stakes

A strike would slow down Samsung while it plays catch-up with its rival. For the first time in 33 years, SK Hynix overtook Samsung as the world’s largest DRAM maker in Q1 last year, driven almost entirely by its dominance in HBM for AI. The next quarter, SK Hynix held 62% of the global HBM market as Samsung slipped to 17%, behind even Micron at 21%. Samsung’s HBM3E chips struggled to pass Nvidia’s qualification standards for much of 2025, while SK Hynix and Micron captured the premium global contracts.

By the end of 2025, Samsung reclaimed the overall DRAM market share lead after shipping HBM to Nvidia and expanding legacy memory production. Its HBM4 chips, which began mass production in February, have reportedly outperformed early expectations, and the entire 2026 HBM4 production run is already sold out. But a prolonged strike could put that turnaround trajectory at risk.

Samsung Chairman Shin Je-yoon said he was “worried about losing market leadership amid fleeing customers and falling competitiveness” in the event of a strike. JPMorgan analyst Jay Kwon has estimated that if Samsung meets the union’s demands in full, 2026 operating profit faces a 7%-12% downside from i