Benzinga's Top #PreMarket Losers

F5 Networks, Inc. FFIV shares dropped 13.70% to $108.70 in pre-market trading after the company announced fiscal first quarter 2015 revenue of $462.8 million, below estimates of $467.25 million. The company also issued a weak Q2 forecast. Xilinx Inc. XLNX shares declined 7.01% to $38.60 in pre-market trading after the company missed third-quarter revenue expectations and offered a disappointing outlook. Drexel Hamilton downgraded Xilinx from Buy to Hold. SanDisk Corp.SNDK fell 6.29% to $75.38 in pre-market trading. SanDisk posted better-than-expected fourth-quarter results and boosted its buyback program by $2.5 billion to a total of $3 billion. However, the company projected current-quarter and full-year 2015 revenue below Wall Street expectations. IxiaXXIA shares dropped 4.76% to $10.00 in pre-market trading after rising 2.04% on Wednesday. American Express Company AXP shares fell 2.03% to $85.89 in pre-market trading. American Express reported stronger-than-expected fourth-quarter results. The company also announced its plans to lower more than 4,000 jobs this year and take a $313 million charge in the fourth quarter.