Trading in an exchange-traded fund that buys leveraged loans soared after billionaire money manager Jeffrey Gundlach said that it could be a good investment for a retiree.

The $6 billion Invesco Senior Loan ETF, ticker BKLN, saw almost 3 million shares worth $69 million hit the tape at 9:45 a.m. in New York on Wednesday, the fund’s biggest block trade since Oct. 22, data compiled by Bloomberg show.

The surge of interest came just hours after Gundlach, the chief executive officer at DoubleLine Capital, identified BKLN in response to a question about where a retired person could invest for a 7% return, while keeping duration and volatility risk low.

“If you’ve got floating rate and you want to get a hope of 7%, you have to buy CLOs middle of the capital structure,” Gundlach said Tuesday on his annual “Just Markets” webcast, referring to collateralized loan obligations. “That’s almost impossible for an individual to do, so absent that, you could buy BKLN.”

BKLN has been attracting assets for the last few months as investors wager that the Federal Reserve will hold interest rates after three consecutive cuts last year. Floating-rate debt, like loans, is particularly sensitive to changing monetary policy, and tends to do better as rates rise. ETFs provide an easy-to-trade way to get exposure to markets that might otherwise be off limits for smaller investors.

However, Gundlach cautioned that anyone who does invest in BKLN should monitor it closely, given that it’s comprised of relatively illiquid loans. If economic data start to falter, that could pressure the fund’s returns.

“You’re going to get downside on BKLN when the economy weakens,” Gundlach said. “It’s not just a buy and put it away.”

--With assistance from John Gittelsohn.

This article was provided by Bloomberg News.