The red hot Nasdaq Biotech ETF (IBB) was up 1.0% in early trading, but it collapsed intraday and closed down -3.4%.
Presidential candidate Hillary Clinton attacked pharma company Mylan (MYL) for raising the price of its EpiPen emergency allergy treatment, which implies that the drug industry could again come under fire over pricing practices.
We also saw many hot momentum stocks like Twilio (TWLO) and Acacia (ACIA) get hit hard.