The fund industry is cashing in on the exuberance around memory stocks.

Shares of the Roundhill Memory ETF, launched April 2, have skyrocketed by around 40% this month through Monday and by more than 98% since inception, according to FactSet data. The fund has rapidly attracted capital, partly because it provides investors with a "specific and differentiated trade idea" as the first exchange-traded fund to focus on high-bandwidth memory stocks, Aniket Ullal, head of ETF research and analytics at CFRA Research, told MarketWatch.

"It's an incredibly successful launch," he said. The ETF, which trades under the ticker "DRAM" as a nod to dynamic random-access memory, has already amassed around $6 billion in assets under management. Underscoring the popularity of the fund's strategy amid the artificial-intelligence boom, another firm recently filed to launch a leveraged ETF designed to magnify the Roundhill Memory ETF's daily performance.

The Roundhill Memory ETF provides exposure to the three companies that dominate the global market share for memory: Micron Technology, SK Hynix (KR:000660) and Samsung Electronics (KR:005930).

There was "latent investor demand" for the Roundhill Memory ETF, Ullal said, because the two biggest exchange-traded funds focused on semiconductor stocks - the VanEck Semiconductor ETF SMH and the iShares Semiconductor ETF SOXX - don't hold SK Hynix and Samsung, both of which are South Korean companies.

Although foreign companies may be listed in the U.S. via American depositary receipts, or ADRs, SK Hynix and Samsung aren't listed on major U.S. exchanges, he said. And because the VanEck Semiconductor ETF and iShares Semiconductor ETF only hold U.S.-listed stocks, there was particularly strong demand for the Roundhill Memory ETF soon after it launched, according to Ullal.

"Samsung and SK Hynix control the majority of global HBM production, but they are listed in South Korea and out of reach for most U.S. investors," Roundhill CEO Dave Mazza told MarketWatch in a statement. "Broad semiconductor ETFs offer minimal pure-play memory exposure."

Micron, SK Hynix and Samsung - the top three holdings of the Roundhill Memory ETF - had a collective weight of around 74% in the fund as recently as Sunday, according to holdings data on Roundhill's website. The fund also offers exposure to storage makers Sandisk, Western Digital and Seagate Technology.

Inflows into the fund spiked late last week, with investors pouring in $1.1 billion on May 7 and adding $906 million the following day, Ullal said. The ETF has seen weekly inflows every week since its inception, he added.

The speed at which the fund has attracted capital is reminiscent of the huge success of the iShares Bitcoin Trust ETF IBIT after the Securities and Exchange Commission approved the launch of the first spot bitcoin ETFs in 2024, he said.

"Daily retail inflows have exploded higher over the past week, the largest daily inflow since launch," analysts at Vanda Research wrote Monday, at which point the fund had just seen $55 million worth of retail net buying.

Some investors now worry that enthusiasm for artificial intelligence has pushed the sector up alarmingly quickly. Yet Themes ETFs has filed a preliminary prospectus to launch a fund designed to provide daily leveraged investment results of two times the daily performance of the Roundhill Memory ETF. It's to be known as the Leverage Shares 2X Long Memory Daily ETF.

Firms that provide leveraged ETFs are "very good at spotting a trend and jumping on it," Ullal said.

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The Leverage Shares 2X Long Memory Daily ETF is "not suitable for all investors," according to the preliminary prospectus for the fund, filed this month with the SEC.

"For periods longer than a single day, the fund will lose money if the performance of the underlying security is flat, and it is possible that the fund will lose money even if the performance of the underlying security increases over a period longer than a single day," the prospectus says. "An investor could lose the full principal value of his/her investment within a single day if the price of the underlying security falls by more than 50% in one trading day."

Paul Marino, the chief revenue officer at Themes ETFs, said in emailed comments that memory "has emerged as one of the most compelling investment opportunities in the AI and high-compute space as compute speed has outpaced memory" bandwidth.

As for the firm's leveraged products, Marino said that they aren't meant to be long-term holdings and that it's "important to note that while an investor has the potential for 200% exposure, that exposure is both up and down." Rather, funds like the leveraged "DRAM" product are designed around "the ease of trading in and out of daily liquid ETFs," he said.

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Ullal cautioned that the leveraged ETFs are "short-term trading tools" used for "high-conviction trades." The Leverage Shares 2X Long Memory Daily ETF would provide exposure to what Ullal sees as a highly concentrated bet on an "already volatile" sector.

Despite the overwhelming demand for memory components, Micron, Samsung and SK Hynix have been reluctant to add capacity out of fear that demand will eventually slow in what is a historically cyclical industry. The supply shortages have allowed them to raise prices, much to the enthusiasm of investors.

Although the companies have now announced efforts to ease supply shortages, their extra capacity is not expected to come online until at least next year, and some analysts expect tightness to continue until 2028.

Micron, SK Hynix and Samsung are also the world's top producers of HBM - a higher-value DRAM product that chip makers, including Nvidia, are hungry for.

Excluding leveraged and inverse funds, semiconductor ETFs listed in the U.S. have attracted $12.5 billion this year through Friday, exceeding inflows of $3.7 billion in all of 2025, according to Ullal.

The VanEck Semiconductor ETF has surged 60% in 2026 through Monday, while the iShares Semiconductor ETF has skyrocketed almost 77% over the same period, FactSet data show.