PIMCO Enhanced Short Maturity (NYSEArca: MINT) was one of the best-selling ETFs in June as more investors are using short-duration ETFs in place of money market funds, which are facing reform measures.

MINT gathered net inflows of more than $700 million last month, according to IndexUniverse data.

“Near-zero yields on money-market funds have led some investors to stash their cash in ultrashort-term bond funds that take a tad more interest-rate risk. Lately, these funds are also attracting people who have become more fearful of rising interest rates, which depress the prices of longer-term bonds,” reports Murray Coleman for Dow Jones Newswires.

He notes MINT is the most popular ultrashort ETF. As of July 5, the fund held $3.8 billion of assets and paid an estimated yield to maturity of 0.98%, according to bond giant PIMCO. Most money market funds are yielding essentially zero due to the Federal Reserve’s low-rate policies. [Ultra-Short-Duration Bond ETFs as a Cash Alternative]

“We like to use MINT as a complement to money-market funds for people who might need cash-like liquidity in the next six months to two years,” says Peter Speros, an adviser at Sullivan, Bruyette, Speros & Blayney, in the Dow Jones report.