Hedge funds managed by Israel Englander and Ken Griffin both scooped up shares in a troubled pharmaceutical stock last quarter.Each quarter, investment firms managing over $100 million are required to file a form 13F with the Securities and Exchange Commission (SEC). These filings provide valuable insight into which stocks the "smart money" investors on Wall Street are buying and selling.Last quarter, Ken Griffin's Citadel and Israel Englander's Millennium Management both bought Pfizer (PFE -0.90%) stock. I ...