I’ve recently been looking into memory. I found that many people can’t quite figure out why, even though they’re both semiconductor stocks, memory stocks are wildly more volatile. After a careful study, it became clear that companies in different parts of the memory industry chain have vastly different risks and returns.

To put it simply, memory concept stocks are divided into three tiers. At the very top are the leading companies that directly produce chips, such as Nanya Technology, Winbond, and Macronix. As long as market quotes rise, their profit sensitivity is the highest—but they’re also hit hardest by the business cycle, with sharp swings both up and down. The midstream consists of companies that control ICs and modules, such as Phison and ADATA. They manage data read/write or process chips into SSDs, and their profits are relatively more stable; their moat comes from software integration. The top tier is made up of international giants like Micron, Samsung, and SK Hynix. Although Taiwanese companies are strong, the global market is essentially dominated by these three, with them holding more than 94% of the DRAM market.

What’s hottest right now is high-bandwidth memory (HBM). Hynix and Micron lead in technology. When these major manufacturers allocate all their capacity to making the HBM needed for AI chips, Taiwanese companies can capture the order-transfer dividend. That’s why recent SSD concept stocks have been performing so impressively.

I checked the latest rankings of the world’s major memory manufacturers. Samsung leads by a wide margin with a market value of $897 billion, followed closely by SK Hynix and Micron. Samsung’s DRAM market share is about 45.5%, and it’s accelerating its pursuit in the HBM space. As the leading HBM shipment company, Hynix is deeply tied to NVIDIA. Micron, meanwhile, is the only U.S. company that has large-scale manufacturing capabilities for both DRAM and NAND, and it’s growing rapidly driven by AI applications.

In Taiwan’s market, Nanya Technology is the most pure-play DRAM concept stock. AI applications have become the main growth driver, and customized AI memory products are starting to contribute revenue. Winbond focuses on niche DRAM and NOR Flash, with a solid presence in consumer electronics, industrial, and automotive fields, avoiding the price-cutting competition of general-purpose DRAM. Phison is one of the companies with the highest purity in NAND Flash. Its revenue and the number of controlled chip shipments are both hitting new highs; currently, the NAND supply shortage is still close to 20%.

The memory industry has a cycle you can’t avoid: shortage → capacity expansion → oversupply → price collapse → production cutbacks → shortage again. This cycle runs through once every few years. Nomura Securities’ latest forecast shows that in the second quarter of 2026, DRAM and NAND prices will rise quarter over quarter by 51% and 50%, respectively. The key is that this industry is extremely capital-intensive. Building a memory wafer fab can cost hundreds of billions of dollars. If you get the investment timing wrong, by the time capacity comes online, the market may have already reversed.

The current situation is that memory prices are still moving upward, and the tight supply situation on the supply side is unlikely to ease in the short term. Holding stocks related to the manufacturing and module segments still has upside momentum. But if your risk tolerance is lower, you can wait to enter after memory stocks fall sharply, because the industry bottom is often the best time to get in. Investors can keep an eye on the DRAM contract price trend, when supply-chain inventory days turn from the highs downward, and whether major manufacturers show any signs of cutting capital expenditures.

In the end, memory stocks aren’t stable growth stocks—they’re cyclical trading assets. What you need to judge isn’t which company you should hold forever, but where the business cycle currently stands. The memory stocks that fell deeply in the previous round became a dark-horse winner in this round due to the AI supply gap. The essence of memory stocks is that you profit from the rhythm, not from the company itself. If you want to flexibly trade related assets for swings or short-term gains, you can consider trading through a CFD platform, so you can go both long and short without needing to hold actual shares.