Related: Biotech ETFs Jump on Gilead, Kite Deal

Year-to-date, investors have added $571.4 million in new assets to XBI.

ETF traders who are betting big on the biotechnology sector rebound have also utilized leveraged long options including the Direxion Daily S&P Biotech Bull Shares (NYSEArca: LABU), which takes the 3x or 300% daily performance of the S&P Biotechnology Select Industry Index. That is the same index XBI tracks.

Other options include the ProShares UltraPro Nasdaq Biotechnology (NasdaqGM: UBIO), which takes the 3x daily performance of the Nasdaq Biotechnology Index, and the ProShares Ultra Nasdaq Biotechnology (NasdaqGM: BIB), which takes the 2x performance of the same benchmark.

For more information on the biotech sector, visit our biotechnology category.