The background to the decline, which was down to around minus 10 percent for a while, was that the company had warned of a significant component shortage. This in turn could affect otherwise strong demand for the company's products such as the iPhone.
Among other losers was the online forum Reddit, whose shares fell 21 percent.
One of the biggest winners on Friday was Amazon, which beat expectations when it presented its interim results on Thursday. The tech giant's stock was up 15.3 percent.
Meanwhile, the New York stock markets as a whole were up. The tech-heavy Nasdaq Composite Index rose 1 percent, the broad S&P 500 Index rose 0.7 percent, while the Dow Jones Industrial Average rose 0.5 percent.
Correction: An earlier version of this text stated the wrong percentage for the Dow Jones. The correct figure should be 0.5 percent.
