Apple shares are down more than 15% from their January high. Amazon’s stock is off 11% from a recent peak in early February. And chipmaker Nvidia has seen its shares plunge nearly 19% since the middle of last month.Apple shares are down more than 15% from their January high. Amazon’s stock is off 11% from a recent peak in early February. And chipmaker Nvidia has seen its shares plunge nearly 19% since the middle of last month.