Biotechnology exchange traded funds are looking under the weather, with investors taking profits after an impressive bull run. Meanwhile, some aggressive traders are capitalizing on Biotech’s misery with the leveraged exchange traded fund.

The iShares Nasdaq Biotechnology ETF (NasdaqGM: IBB) saw $70 million in outflows over the past month, according to data. The ETF declined 11.1% over the past month. [Biotech ETFs Hold Their Breath]

Meanwhile, the ProShares Ultrashort Nasdaq Biotechnology (NasdaqGM: BIS), which attempts to deliver twice the daily inverse performance of the Nasdaq Biotechnology Index, IBB’s underlying index, has attracted $20.4 million in assets over the past month while the ETF surged 22.4%. [A Gutsy Technical Call on a Biotech ETF]

“There’s a little bit of nervousness about some of the high multiples in the biotech area and computer and Internet-related stocks,” John Carey, a fund manager at Pioneer Investment Management Inc., said in a Bloomberg article.. “You’re having another wave of selling in that very high-momentum group.”

Only three of the 121 companies listed on the Nasdaq Biotechnology Index declined Friday, led by a 28.5% drop in Halozyme Therapeutics (NasdaqGS: HALO).

Halozyme stocks plummeted after the company ordered a temporary halt on a mid-stage clinical trial for pancreatic cancer treatment due to blocked blood vessel symptoms, according to the Associated Press.