Technology stocks are having a bumper year. Despite a recent wobble, the share price of the Big Five—Alphabet, Amazon, Apple, Meta and Microsoft—has jumped by 60% since January, when measured in an equally weighted basket (see chart 1). The price of shares in one big chipmaker, Nvidia, has tripled and in another, amd, almost doubled. Their price-to-earnings ratios (which measures how much the markets think a company is worth relative to its profits) are ten times that of the median firm in the s&p 500.