What happened

Shares of Comcast (CMCSA -0.52%) were hit hard on Thursday, falling as much as 7.2%. The stock finished the trading day down 6.2%.

The stock's sharp sell-off comes as Comcast's vice president of Xfinity services, Matthew Strauss, said during a Merrill Lynch investor conference on Thursday that the company expected to lose about 100,000 to 150,000 video subscribers during its third quarter. 

Man holds remote toward a wall of video thumbnails

Image source: Getty Images.

So what

A loss of 100,000 to 150,000 video subscribers would mark a steep decline compared to the second quarter, when the company's total video customer net losses were 34,000. 

Strauss cited heightened competition and Hurricane Harvey for the expected loss in subscribers, though he didn't specify what portion of these losses Comcast expects to be driven by each cause.

It was Comcast's "most competitive quarter" in recent history, Strauss said according to CNBC.

Now what

For some perspective, Comcast had about 22.5 million video subscribers at the end of its second quarter. So, while a quarterly loss of subscribers of 100,000 to 150,000 would be concerning if it proves to be a prolonged trend, investors should look for more commentary from management to see whether Comcast believes it can navigate these challenges and reverse the decline.