SanDisk Corp. (NASDAQ: SNDK) fell 4.7% to $76.69. 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. Share volume was 8.1 million, compared to an all-day average of 3.4 million