Issuers of exchange-traded funds (ETFs) continue to bring plenty of new products to market. While Wall Street is supposedly in the midst of the summer doldrums, more than a dozen new ETFs debuted just last week, including some new fixed income funds. Plenty of new bond funds have launched this year, and there is ample talk about the smart beta phenomenon permeating the bond ETF space in earnest. While some new, unique bond ETFs may ultimately prove successful, the reality among rookie bond ETFs this year is that boring is beautiful.

Two of this year's most successful new bond ETFs are boring, and that is not an insult. The PowerShares Treasury Collateral Portfolio (CLTL) debuted on Jan. 12 and now has nearly $372 million in assets under management, making it one of this year's most successful new ETFs, fixed income or otherwise. Only five PowerShares ETFs have seen greater year-to-date inflows than CLTL. (See also: 4 Big ETF Launches of Q1.)

CLTL tracks the ICE U.S. Treasury Short Bond Index, which "measures the performance of U.S. Treasury Obligations with a maximum remaining term to maturity of 12 months" according to PowerShares. While PowerShares, the fourth largest U.S. ETF issuer, carefully notes that CLTL "is not a money market fund and does not attempt to maintain a stable net asset value (NAV)," the ETF is a suitable alternative to cash instruments. CLTL's 75 holdings are of high credit quality, and the ETF has an effective duration of less than 0.4 years, so interest rate risk is not a concern.

Not to be outdone, there is the Goldman Sachs TreasuryAccess 0-1 Year ETF (GBIL). To be fair, GBIL debuted in September, so it is around 10 months old. Still, a 10-month-old ETF with assets under management of over $635 million is noteworthy. GBIL has swelled in size thanks to a recent spate of inflows. As its name implies, GBIL is no more sexy than CLTL. The Goldman Sachs ETF follows the Citi US Treasury 0-1 Year Composite Select Index, which holds Treasuries with maturities of no more than one year. (See also: Goldman Sachs Adds a Corporate Bond ETF.)

"GBIL is the first to offer multiple Net Asset Values, adding additional price transparency," according to Goldman Sachs. GBIL has 13 holdings and an effective duration of just 0.37 years. Although it may be seen as boring, the Goldman ETF is also cheap – it charges just 0.12% per year, or $12 on a $10,000 investment. (For related reading, check out: Top 5 Bond ETFs for 2017.)