For several years, the stocks of America's Internet giants — Facebook, Apple, Amazon, Google — have been the way to make money. And yet, for all their past prowess, these four companies all have major weaknesses in their business models that are becoming increasingly apparent.
They could thus be destined for a replay of the 1999 dot-coms, the 1972 Nifty Fifty, the 1929 Investment Trusts or the 1720 South Sea Company.