The funds with the word "Treasury" in their titles invest solely in Treasuries, the funds with the word "credit" are corporate bonds, and the funds with the words "government" and "credit" are a blend of Treasuries and corporates. These funds will help investors in some aspects but come up short in others. The bond ETFs that already existed were not a complete set, and where the treasury ETFs are concerned, SHV, IEI and TLH clearly fill the gaps. They give investors more specific control and management over their average maturity, plus the chance to reallocate in anticipation of interest rate changes, which, if done correctly, could serve to reduce bond portfolio volatility. These funds could also be a handy tool for institutional investors looking to speculate on various spreads across the yield curve getting narrower or wider. Combinations of two or more ETFs in various long/short permutations allow for some very sophisticated uses. The corporate and corporate/govie funds allow for more of the same between different fixed-income products, which creates an obvious path to foreign-bond ETFs, along with other segments within the bond market.