Shares of Apple Inc. are on a rollercoaster ride this week, fluctuating wildly. The shares went from ~$124 on Wednesday to ~$112 on Thursday, then back up to ~$122 on Friday. The reason for the dip may have been pure profit taking by investors who have seen tremendous gains in the stock this year. The shares are up nearly 80% from a year ago. American Technology Research analyst Shaw Wu told Macworld UK. "The stock's been a huge outperformer, and I think it's just [investors] taking some profits. It's probably one of the few names people have made a lot of money on." The recent surge, meanwhile, is likely due to an overall bump in the market brought about by Federal Reserve Board's announcement Friday that it was cutting its discount rate by 50 basis points, to 5.75%, from 6.25%. "Banks use the so-called discount window to borrow money directly from the Fed, rather than from eachother, which is the more common way that they obtain short-term financing." The Fed also lengthened the period of borrowing at the discount to a 30-day term, renewable by the borrower, from the previous overnight loans. Just before the close of trading, Apple's shares were up about 4 percent.