High-yield bonds also have been in favor among bond investors amid the search for yield and ratcheting up of the risk profile.
While high-yield is volatile, Tucker said, "the fundamentals look very good." Corporations are sitting on piles of cash, defaults are low and Fed policy has been accommodative.
Price appreciation may not be as great as it had been in high-yields, such as the iShares iBoxx Hi Yld Corp (HYG), but the income opportunity is still strong, he said.
"Five percent clipping a coupon, if interest rates don't go through the roof, if they don't, that's not a bad proposition," said Bob Pisani, CNBC "On-Air Stocks" editor in his interview with Tucker at ETF.com's Inside ETFs conference in Hollywood, Florida.
The emerging market fiasco has investors moving to Treasurys. It's no different in emerging market bond ETFs: Expect a bumpy ride, Tucker said.
If you are already in a fund such as IShares JPMorgan USD Emerging Markets Bond ETF (EMB), hold on to it, as investors likely will be able to ride it out, he said. If you are looking to buy into emerging market bonds now, though, it may not be the best time.
—By Anthony Volastro, Segment Producer, CNBC. Follow him on Twitter