(Bloomberg) — A new exchange-traded fund attempting to carve out a slice of the $6.3 trillion sitting in traditional money-market funds is launching Wednesday.

The Texas Capital Government Money Market ETF begins trading under the ticker MMKT, according to a press release. While other short-dated bond ETFs exist, MMKT is the first to follow the so-called Rule 2a-7 — a provision of a 1940s Securities and Exchange Commission law that governs money-market funds. 

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MMKT’s portfolio will have the characteristics of a traditional money-market fund and be governed by the same SEC provision, there’s one crucial difference: MMKT won’t maintain a stable net-asset value of $1.

“Money markets have gone unchallenged since ETFs began,” said Edward Rosenberg, head of ETF and funds management for Texas Capital. “Money market funds are viewed as cash equivalents, and no other ETF has that designation.”

For investors wondering why they might want a vehicle with less stable capital preservation, the Dallas-based lender — which launched its first ETF last year — says there’s been growing acceptance of floating values for government money-market and prime funds. MMKT also provides institutional investors more intraday liquidity than a traditional money-market account, according to the bank.

Assets in money market funds have skyrocketed over the past several years, thanks in a large part to an aggressive Federal Reserve hiking cycle that left short-term rates north of 5%. Investors flocked to those relatively lofty yields, boosting money-market funds to an all-time high of $6.3 trillion this month. While the central bank has since embarked on rate-cutting campaign, Texas Capital sees an opportunity to capitalize on the still-strong demand for cash.

“It’s a little fancier than just your straight-up Treasury bill ETF, and an interesting marketing spin,” said Todd Sohn, an ETF strategist at Strategas.

MMKT, which carries an annual expense ratio of 20 basis points, must invest 99.5% of its assets in cash or short-dated government securities. The maturities of its holdings can be as short as overnight, in the form of repurchase agreements, or as long as 13 months, according to SEC filings. 

That’s a key distinction with existing cash-like ETFs. Take the $34 billion SPDR Bloomberg 1-3 Month T-Bill ETF (ticker BIL) — while virtually all of the fund’s holdings are in short-dated government paper, BIL’s prospectus only mandates that at least 80% of its assets be in such holdings. It carries a 0.14% expense ratio.