Disney, Viacom, Time Warner and 21st Century Fox were just some of the media companies suffering on the stock market this week. Drops on Wednesday wiped out $37 billion in market capitalization among those companies and others. The fear is that media companies will continue to lose profits as more and more people cut the cord or younger viewers never sign up for cable in the first place. Viacom especially took a tremendous hit. The company has been struggling for a while, and today they lose their most popular person on Comedy Central -- Jon Stewart. Nickelodeon, another Viacom property, continues to lose young audiences to streaming services like Netflix. News of the struggles on Wall Street hit as television critics sat through the summer press tour at the Beverly Hilton. The most buzzed about presentations so far haven't been traditional TV networks at all, but Netflix and Amazon.