Former hedge fund superstar Stanley Druckenmiller sold his Broadcom position and added shares of MercadoLibre in the third quarter.Billionaire Stanley Druckenmiller was one of the most successful hedge fund managers in history, generating returns of 30% annually over three decades without a single down year. He closed his hedge fund in 2010, and now exclusively manages his own money through Duquesne Family Office.In the third quarter, Druckenmiller sold his entire stake in Broadcom (AVGO +3.18%) and bought ...