SK Hynix stock jumps as they get Microsoft Maia 200 AI chip deal

SK Hynix (HXSCL) stock just ripped almost 9 percent overnight because it locked down the most important thing in AI hardware right now.

Memory.

A local report says SK Hynix will be the sole supplier of advanced memory for Microsoft’s (MSFT) next in-house AI chip, Maia 200.

That single detail pushed South Korea’s market to an all time high and turned a good year for SK Hynix into a great one.

The deal matters because it is not experimental. Microsoft has already installed Maia 200 in an Iowa data center and is expanding deployment in Arizona.

Maia 200 is built on a 3 nanometer process from Taiwan Semiconductor Manufacturing Co. and each chip packs 216 gigabytes of HBM3E memory. All of that memory comes from SK Hynix. No second source. No fallback supplier.

That exclusivity is why the stock moved. The market understands what is happening even if most headlines do not.

The disruption behind the news: This deal redraws the AI chip market.

For years Nvidia owned the AI stack by controlling both the accelerator and the memory ecosystem around it.

Hyperscalers talked about custom chips but rarely shipped them at scale. Microsoft just crossed that line.

Here is the real disruption. Memory, not compute, is now the choke point. Memory is also one of the 4 AI bottlenecks. HBM3E is scarce, hard to manufacture, and impossible to swap out once a system design is locked.

Each Maia 200 uses six 12 layer stacks. Multiply that across thousands of accelerators per data center and you get a brutal supply constraint.

By becoming the sole supplier, SK Hynix effectively becomes part of Microsoft’s internal silicon team. Switching costs are enormous. You do not redesign a 216 gigabyte memory subsystem lightly. That locks in pricing power and volume visibility for years, not quarters.

For Microsoft, this is about margin control and leverage. Owning the chip lets it negotiate harder with Nvidia, tune hardware for its own models, and lower inference costs over time. Even a 10 percent reduction in per token cost at Azure scale moves billions.

For competitors, this is a warning shot. Amazon and Google already build custom silicon, but neither has publicly locked down next generation HBM supply this tightly. If you do not secure memory early, you do not ship on time. Period.

This also explains why the broader semiconductor sector jumped more than 6 percent. Capital is rotating toward companies that sit inside the AI cost curve.

What to watch next

First, watch memory pricing.

HBM3E prices are already elevated, but exclusivity deals like this keep supply tight into 2026. That supports margins even if DRAM pricing softens elsewhere.

Second, watch deployment scale.

If Microsoft ramps Maia 200 beyond internal workloads and pushes it deeper into Azure, expect follow on designs. Maia 300 will not wait for a new supplier.

Third, watch earnings next week.

When Samsung Electronics and SK Hynix report, listen for capacity language. Any hint of constrained HBM output means this deal just got more valuable.

Finally, watch regulation and trade noise fade into the background.

Tariff threats did not stop this rally because they do not touch the core bottleneck. AI infrastructure demand overwhelms politics.

The simple truth is this. In AI, whoever controls high bandwidth memory controls the pace of progress, and right now SK Hynix is tightening the valve. Microsoft (MSFT) has a Disruption Score of 3. Click here to learn how we calculate the Disruption Score. 

Microsoft is also part of the Disruption Aristocrats, our quarterly list of the world’s top disruptive stocks.