SK Hynix Stock: Is It a Good Long-Term Buy After Its Record Run?

TLDR

• SK Hynix posted record Q1 2026 revenue of 52.57 trillion won, with profit rising more than fivefold year-over-year
• The company is Nvidia’s primary supplier of HBM3E, making it a core part of the AI chip supply chain
• AI inference growth is lifting demand beyond HBM into server DDR5 and enterprise SSDs
• SK Hynix has overtaken Samsung as South Korea’s most valuable listed company, joining the $1 trillion market-cap club
• Competition from Samsung and Micron, heavy capex plans, and a stretched valuation are the main risks going forward

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SK Hynix just posted the best quarterly numbers in its history. Q1 2026 revenue came in at 52.5763 trillion won, with operating profit of 37.6103 trillion won and net profit of 40.3459 trillion won. Profit was up more than fivefold from a year earlier.

The driver is no secret: high-bandwidth memory. HBM is the premium memory that sits inside Nvidia’s AI accelerators, and SK Hynix is the dominant supplier. That single product has reshaped what kind of company this is.

Nvidia relies heavily on SK Hynix for its 12-layer HBM3E chips. That dependency has given the South Korean chipmaker pricing power and a supply-chain position that competitors are scrambling to match.

The story is also getting broader. SK Hynix says AI inference growth is pulling demand into server DDR5 and enterprise SSDs — not just HBM. When demand spreads across a product portfolio like that, it tends to make the overall business more durable.

That breadth has shown up in the market cap. SK Hynix crossed the $1 trillion valuation mark earlier this year and has since overtaken Samsung as South Korea’s most valuable listed company. That is a major rerating for a name that was posting heavy losses during the last memory downturn.

The balance sheet has also improved sharply. The company moved into a net cash position, giving it room to invest in capacity while keeping financial flexibility. In a capital-heavy industry, that matters.

Growing Competition and Capex Pressure

Samsung and Micron are not standing still. Both are pushing hard into HBM, and in a market this profitable, they will contest market share aggressively. SK Hynix’s lead is real, but it is not guaranteed to last forever.

Capex is the other pressure point. SK Hynix plans to double wafer capacity over the next five years. That reflects strong demand signals, but it also means the company has to keep deploying capital at scale without tipping into oversupply.

Valuation Is the Honest Conversation

The easy money in SK Hynix has likely already been made. A year ago, the stock was a cyclical recovery play with a beaten-down valuation. That window is closed.

Today it trades as a premium AI infrastructure name. Investors are pricing in continued technology leadership, sustained HBM demand, and ongoing earnings power. That is a higher bar to clear.

It still looks like one of the best pure-play AI memory names in the world. The customer relationships are strong, the product roadmap is ahead of rivals, and the financial results back up the narrative.

But investors buying now are paying for a company that has already proven itself — not one the market is still figuring out. Future returns will depend on SK Hynix extending its technology lead, not just riding the wave it caught first.

The most recent data point: SK Hynix overtook Samsung as South Korea’s most valuable listed company in June 2026, capping a turnaround that few saw coming at this speed.