Comcast shares fell by almost 5%, and Charter, Cablevision, and Time Warner Cable all fell to varying degrees. Media stocks saw worse: shares of Time Warner, Inc fell by 9% on Wednesday, Discovery Communications Inc shares fell by 12%, 21st Century Fox shares fell by 7%, Viacom by 7.5% and Disney by 9.2%.

Analysts say that despite cord-cutting being a relatively small real impact on cable businesses and pay-TV in general, it still has investors spooked.

"Cable operators are not media companies; they are infrastructure providers," said Craig Moffett of MoffettNathanson. "On the other hand, we have been warning for the past six months that a quickening of the pace of cord-cutting was likely during the second quarter and that cable stocks were likely to suffer as a result. Indeed, our relatively cautious stance on the cable stocks for the past two-and-a-half years, after so many years as an inveterate 'cable bull,' has been that cord-cutting would pressure the cable video distribution profit pool at precisely the time that regulatory pressure was mounting on broadband pricing, and that this interplay between technology change and regulatory scrutiny would necessarily raise questions about terminal growth rates and therefore warranted multiples."

He doesn't expect things to end here either. "We'll be looking for a bigger pullback in valuations and, just as importantly, a qualitative sense that sentiment really has shifted, before we get more constructive," he concluded.