Three companies. Nearly three-quarters of a fund’s entire portfolio. The Roundhill Memory ETF, trading under the ticker DRAM, has placed roughly 74.8% of its assets in Micron Technology, Samsung Electronics, and SK Hynix.

But investors don’t seem to mind. The fund hit $1 billion in assets under management within about 10 days of its April 2, 2026, launch. That kind of inflow velocity has drawn direct comparisons to the spot Bitcoin ETFs that reshaped crypto markets when they debuted.

Inside the concentration play

As of July 5, 2026, Micron Technology leads the portfolio at 25.96%, followed closely by Samsung Electronics at 25.40% and SK Hynix at 23.46%. Together, these three memory chip giants account for the vast majority of the fund’s exposure.

The remaining quarter or so is spread across other memory semiconductor names and related companies, with the ETF using a mix of equities and derivatives to build its positions. It carries an expense ratio of 0.65%, which sits in the mid-range for thematic ETFs but is notably higher than broad market index funds.

Why this matters beyond semiconductors

The speed of DRAM’s asset accumulation tells us something broader about how capital moves in 2026. Reports suggest the ETF’s assets under management have reached somewhere in the range of $6 billion to $24 billion, though estimates vary.

The European market noticed. A counterpart fund, the Defiance Memory UCITS ETF, launched on June 18, 2026, and had accumulated approximately $60 million in assets by early July.

What investors should watch

Capital expenditure plans from major cloud providers and AI labs are the leading indicator to watch. If hyperscalers like Microsoft, Google, and Amazon start trimming their AI infrastructure budgets, memory demand forecasts get revised downward, and an ETF with 75% exposure to three companies in that exact supply chain faces significant pressure.

There’s also the geopolitical dimension. Samsung and SK Hynix are South Korean companies with significant manufacturing exposure in regions subject to trade tensions. Micron operates globally but has faced its own regulatory challenges in China.