Apple shares were down 4 percent in morning trading, putting them below the $500 mark for the first time since February.
Zynga shares were falling in after-hours trading after the online game company and Facebook disclosed in government filings that they changed the terms of their long-standing relationship.
Yahoo’s shares have touched $19 Monday, marking the first time they have traded that high in more than two and half years.
Shares of Ruckus Wireless Inc. fell Friday after raising $126 million in an initial public offering of stock.
Facebook’s biggest lock-up period – a time following an IPO that prevents insiders from selling stock – expires on Wednesday.
Apple’s stock fell Wednesday along with a sharp sell-off in the broader market as investors, with the election behind them, dumped stocks and turned their focus to a world of problems – tax increases and spending cuts that could stall the nation’s economic recovery and a deepening recession in Europe.
Less than a week after activist investor Carl Icahn announced a 10 percent stake in Netflix, the online video company is moving to protect itself against hostile takeovers.
Facebook’s stock price fell Wednesday, the day employees were eligible to start selling restricted stock in the company.
Apple’s stock fell below $600 Friday for the first time in three months, after the consumer electronics behemoth warned that costs of making new products will cut into profits in the holiday quarter.
Facebook shares are posting their biggest single-day gain since going public, jumping 21 percent after the social media company made inroads in mobile advertising and posted accelerating growth in overall ad revenue.