-- Tech stocks advanced Tuesday afternoon, with the State Street Technology Select Sector SPDR ETF (XLK) up 0.2% and the State Street SPDR S&P Semiconductor ETF (XSD) adding 1.5%.
The Philadelphia Semiconductor index increased 0.4%.
In corporate news, Apple (AAPL) announced that Tim Cook will step down as chief executive of the iPhone maker and become executive chairman, with hardware engineering veteran John Ternus set to succeed him as CEO. Apple shares were down 2.5%.