DRAM 的集中度很高：其 73% 资产集中于三家公司——韩国的 SK Hynix、Samsung Electronics，以及美国的 Micron Technology；Micron 周二一度上涨 19%，市值升至 1 兆美元以上。相比之下，BAI 持有较广泛的美国晶片股，包括 Broadcom、Nvidia 和 AMD。受此题材推动，AI 与大数据 ETF 及共同基金自 2025 年初以来规模已翻倍以上，达 708 亿美元，主要由资金流入带动，而非市场涨幅。
分析师将这波买盘视为 AI 基础设施热潮的一部分，因投资人押注未来 5 年约 7.6 兆美元将投入 AI 资料中心与相关运算晶片；同时，市场也在期待 SpaceX、Anthropic 与 OpenAI 的大型上市，合计估值可能达 4 兆美元。不过，Morningstar 研究指出，主题型 ETF 往往因投资人追高杀低而落后其主题本身，Daniel Sotiroff 也警告，当前微晶片 ETF 估值偏高，且 DRAM 的三档持股彼此高度相关，风险集中。
Roundhill Memory ETF, known as DRAM, reached $10bn in assets just 50 calendar days after its April 2 launch, making it the fastest ETF on record to hit that valuation. The fund rose 87% from launch and pulled in $8.6bn of inflows, far quicker than the iShares AI Innovation and Tech Active ETF, or BAI, which took 556 days to reach $10bn.
DRAM is highly concentrated: 73% of assets are in three companies — South Korea’s SK Hynix and Samsung Electronics, plus Micron Technology in the US. Micron briefly gained as much as 19% on Tuesday, lifting its market value above $1tn. By contrast, BAI offers broader exposure to major US chipmakers such as Broadcom, Nvidia and AMD. AI and big data ETFs and mutual funds have more than doubled since the start of 2025 to $70.8bn, driven mainly by inflows rather than market gains.
Analysts see the rush as part of the AI infrastructure boom, with investors betting that about $7.6tn will be spent over the next five years on AI data centres and the semiconductors needed to power them. The market is also anticipating major listings from SpaceX, Anthropic and OpenAI, with a possible combined valuation of $4tn. Still, Morningstar warns that thematic ETFs often lag their themes because investors buy high and sell low, and Daniel Sotiroff said current microchip ETF valuations look stretched and DRAM’s three holdings are closely related.