For the Daring, Short Treasury ETFs

The iShares 20+ Year Treasury Bond ETF (NYSEArca: TLT) gained nearly 4% last month while the iShares 7-10 Year Treasury Bond ETF (NYSEArca: IEF) tacked on 1.3%.

Since the start of the third quarter, only three ETFs have added more new assets than IEF and last month, IEF was the top asset-gathering ETF. Not just among bond ETFs, but among all ETFs. Those anecdotes speak the difficulty and risk in being short Treasury ETFs during a year in which 10-year Treasury yields have tumbled 19%.

Still, some market observers see the rally in Treasury ETFs, particularly the longer-date variety such as TLT, as a case of too far too fast.

In a note out Wednesday, MKM Partners recommended shorting TLT noting “that as of Friday TLT was up nearly 17% YTD on an absolute basis and nearly 19% on a total return basis, which would rank as the ETF’s third-best year since its creation in 2002, trailing only 2008 and 2011, both of which gained over 28%,” reports Michael Aneiro for Barron’s.

MKM’s downside targets for TLT are $113 to start and then $110, according to Barron’s. Neither represents significant downside for the $4.2 billion, which in August posted its best monthly performance since January. [Treasury ETFs Rally in August]

Only three ETFs have added more new assets this year than IEF and the Treasury-heavy Vanguard Total Bond Market ETF (NYSEArca: BND) and the iShares Core U.S. Aggregate Bond ETF (NYSEArca: AGG) both rank among the top-10 asset-gathering ETFs.