It was a frequent event in the month of August. Throughout the month, daily checks of exchange traded funds making new all-time highs turned up plenty of health care funds.

Much to the chagrin of the biotechnology bears that growled so loud late in the first quarter and early in the second, biotech ETFs were not tailing the performances of broader health care funds last month. They were doing the leading.

The First Trust NYSE Arca Biotechnology Index Fund (NYSEArca: FBT) “popped 14% to an all-time high last month, outperforming all nonleveraged ETFs. It has rocketed 57% from a 52-week low of 59.09 amid a brightening sector outlook,” reports Aparna Narayanan for Investor’s Business Daily.

FBT was already cruising toward a solid August performance when, late in the month, Swiss pharmaceuticals giant Roche announced it will acquire InterMune (NasdaqGS: ITMN) for $8.3 billion in cash. Before that deal was announced, FBT had the largest weight to InterMune of any of the five major biotech ETFs. [InterMune Deal Lifts Biotech ETFs]

The PowerShares Dynamic Biotechnology & Genome Portfolio (NYSEArca: PBE) was also fortunate enough to count InterMune among its top-10 holdings at the time the Roche deal was announced, helping the ETF surge 11.1% last month. Although it closed slightly lower, PBE touched a new all-time Monday.

PBE has previously benefited from biotech mergers & acquisitions news. The ETF surged in June when Merck (NYSE: MRK) said it would acquire Idenix Pharmaceuticals (NasdaqGS: IDIX) for $3.85 billion. At the time the deal was announced, Idenix was PBE’s ninth-lagest holding with a weight of 3%. [Why These Biotech ETFs are Soaring]