The biotech sector performed well in August, with the iShares Nasdaq Biotechnology ETF (NASDAQ: IBB) up almost 3.5% this week alone.

Research by Raymond James indicates that in just the past week, biotech funds saw $510 million in capital inflows. This in part led major biotech companies like Biogen Inc (NASDAQ: BIIB) and Celgene Corp (NASDAQ: CELG) to post solid returns this week.

In the same report, Raymond James analyst Laura Chirco said “we continue to see biotech sector performance being influenced by several drivers: data readouts, commercial execution, M&A potential and capital markets accessibility. Biotech fund flows — including ETF activity — remain a driver to watch.”

CNBC analyst Meg Tirrell identifies three main drivers for biotech growth: company-specific news, the FDA’s stance, and drug pricing outlook.