There was a time when top executives narrowed their sights very little. Any type of business was fair game. But in the 1990s the idea of the conglomerate, the holding company with a diverse portfolio of businesses, went out of fashion as some of its most prominent protagonists—CBS and Hanson Trust, for example—faltered. Companies found they could add more value by sticking to their knitting, their “core competence”, although one of the most successful companies of that decade, General Electric, was little more than an old-style conglomerate with a particularly fast-changing portfolio.