Junk bond ETFs such as iShares iBoxx High Yield Corporate Bond (NYSEArca: HYG) and SPDR Barclays High Yield Bond (NYSEArca: JNK) are more sensitive to credit risks than interest-rate risk, relative to Treasuries.

However, that doesn’t mean the junk debt funds have been immune to the spike in Treasury yields this month.

Investors seeking to maintain exposure to high-yield corporate bonds but who want to reduce interest-rate risk are rotating into funds with shorter durations such as PIMCO 0-5 Year High Yield Corporate Bond Index (NYSEArca: HYS) and SPDR Barclays Short-Term High-Yield Bond ETF (NYSEArca: SJNK). [Two High-Yield Bond ETFs for Rising Rates]

For example, SJNK has held up better in May than its counterpart JNK, which holds junk bonds with longer durations.

JNK has a modified adjusted duration of 4.24 years, versus 2.19 years for SJNK, according to manager State Street Global Advisors.

HYS, the PIMCO high-yield ETF, has an effective duration of 1.92 years.

“HYS has a lower duration than its competitors in the high-yield bond category, which means that the fund will be less affected by rising interest rates,” according to a Morningstar analyst report on the ETF.

Rock-bottom Treasury yields and short-term interest rates have forced income investors to take on more risk in search of yield. Junk bond ETFs have been a recipient of a decent chunk of this cash. However, bond investors are worried about the damage that higher interest rates could inflict on their funds. Bonds yields and prices move in opposite directions.

Rising interest rates have come into focus as the economy improves and on talk the Federal Reserve may scale back its bond purchases.

Next page: Rate-hedged and defined-maturity ETFs