A foul wind blows south from here.

It can and did, obviously. Already down about 15% since last Friday, the iShares Nasdaq Biotechnology ETF showed that it was still a biotech ETF yesterday, riding the sector’s swoon to its worst day ever to punctuate its worst seven days ever.

The $809 million SPDR S&P Pharmaceuticals exchange-traded fund (XPH) shed 8.4%, while the iShares Nasdaq Biotechnology ETF (IBB) dropped 6.3%.

The formerly high-flying biotechnology ETF has now lost 20% over the past seven trading sessions….

One trader said that the selling “feels heavily index driven,” meaning that investors are bailing on index-tracking exchange-traded funds — and fast. Trading volume in the IBB hit a record 11.7 million shares on Monday, topping its previous record — 9 million — hit on Friday.

Capitulation In Biotech? ETF Suffers Biggest One-Day Drop Since 2011 [WSJ MoneyBeat blog]
Dow Industrials Sink 313 Points [WSJ]