What happened

Don't look now, but shares of cable TV and internet-giant Comcast Corporation (CMCSA -0.37%) just shorted out, crashing 5.4% through 11:15 a.m. EDT -- and it has only itself to blame.

More precisely, it has CFO Michael Cavanagh to blame.

Glowing red stock chart arrow trending down

Image source: Getty Images.

So what

Speaking at an investor conference this morning, Cavanagh revealed that Comcast is looking to "trend in line for third quarter net adds with historical averages for third quarter, but ... be behind the third quarter 2019, which was a record third quarter," reports TheFly.com today. In a separate report on the same conference, StreetInsider.com added that Comcast's customer additions slowed "a little bit" when Covid outbreaks "interrupted traditional patterns of customers moving and returning to school" in August.

Now what

What does this mean for investors?

Investment bank KeyBanc says Cavanagh's comments are a "modest negative" for Comcast. Doing a bit of back-of-the-napkin pencil work, the banker calculates that Comcast is now probably expecting to add only about 300,000 net subscribers to its internet services in Q3. That's well below the 403,000 subscribers that most analysts have been forecasting, however.

That suggests the "negative" could actually be anything but "modest" when Comcast's Q3 results roll out at the end of October. Analysts are looking for about a 15% increase in Comcast's profits for this Q3, currently underway, but if net additions continue to trend as much as 25% below expectations, that earnings projection could be in jeopardy. 

Long story short: Comcast could miss earnings in Q3. And if the trend of weaker-than-expected subscriptions continues, it may potentially miss more than just in Q3.