Maybe the second time will be the charm: With a group of Internet companies reporting values of more than $70 billion, could there be a second dot-com bubble? There are some key similarities: banks pouring money into technology funds, wealthy backers fighting to get in on the startup action, and expectations of stock-market debuts building. But there are some differences as well: In 1999, the peak year of the dot-com bubble, 308 tech companies went public, while only 20 went public in 2010—and none of the biggest Internet giants have gone public. Some argue there is a “frenzy” going on now as in the late 1990s, but the notable difference is that the energy is going into the giant companies, like Facebook and Groupon.