One of the Hottest ETF Trades

As exchange-traded funds continue to see asset inflows, one ETF has been popular among investors, ProShares Advisors Head of Capital Markets Steve Sachs said Monday.

"On the equity side, it's been into things like ticker CSM," he said. "It's based on the Credit Suisse 130/30 Index, and it's a long-short equity product."

On CNBC's "Fast Money," Sachs said that the ETF provided a way for investors to participate in the stock market rally but with some peace of mind.

"So, while there's lots of believers in the bull market that we're in and the rally we've had, a lot of people still want to dedicate assets and continue to put new money toward equity and capture the equity risk premium, but they want to do it in a hedged fashion, you know, as opposed to just making outright beta bets in the marketplace," he said.

Trader disclosure: On May 20, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Simon Baker is long AAPL; Simon Baker is long C; Simon Baker is long GS; Simon Baker is long JPM; Simon Baker is long CSCO; Simon Baker is long YHOO; Simon Baker is long GOOG; Simon Baker is long EBAY; Simon Baker is long PCLN; Simon Baker is long JCP; Jon Najarian is long JPM; Jon Najarian is long ZNGA; Jon Najarian is long HLF; Jon Najarian is long DAL; Jon Najarian is long LCC; Jon Najarian is long XLF; Jon Najarian is long JCP; Jon Najarian is long NTAP; Jon Najarian is long OC; Jon Najarian is long TMO; Jon Najarian is long GTAT; Jon Najarian is long EMC; Jon Najarian is long COP; Jon Najarian is long GRPN; Joe Terranova is long VRTS; Joe Terranova is long SJM; Joe Terranova is long SPLK; Joe Terranova is long LNKD; Joe Terranova is long TBT; Joe Terranova is long SWN; Joe Terranova is long JULY CRUDE OIL FUTURES; Stephanie Link is long AAPL; Stephanie Link is long GS; Stephanie Link is long JPM; Stephanie Link is long WFC; Stephanie Link is long CSCO; Stephanie Link is long FB; Stephanie Link is long EBAY; Stephanie Link is long TJX; Stephanie Link is long HD; Stephanie Link is long SWK.