MINT, which is rated marketweight by S&P, holds the bulk of its assets in corporate bonds and has a duration of less than a year with a  30-day SEC yield of half a percent. [6 Ultra-Short Duration Bond ETFs]

S&P is more enthusiastic about the newly-minted iShares Short Maturity Bond ETF (NYSEArca: NEAR), which the research firm rates overweight.

“Just over three months old, NEAR does not have a long-term track record to point to like MINT, but we think it offers investors a nice alternative and has done a good job of gathering assets,” said S&P Capital IQ. “However, from a credit perspective, NEAR has greater exposure to BBB rated bonds and less exposure to AAA rated bonds than MINT. This ETF also has two-thirds of its assets in corporate bonds.”

Like MINT, NEAR is actively managed. The iShares offering already has almost $183 million in assets under management and is inexpensive by the standards of an actively managed ETF with annual fees of just 0.25%.

PIMCO Enhanced Short Maturity