What happened Don't look now, but shares of cable TV and internet-giant Comcast Corporation (NASDAQ: CMCSA) 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. 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. 10 stocks we like better than ComcastWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Comcast wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of August 9, 2021 Rich Smith has no position in any of the stocks mentioned. The Motley Fool recommends Comcast. The Motley Fool has a disclosure policy.Source