Comcast Corp.'s (CMCSA) - Get Report strong post-earnings rally is over. It lasted just one day. The stock closed Thursday down 1.76% at $36.24. 

Comcast shares closed 5.5% higher Wednesday, after topping analysts' fourth-quarter expectations and boosting its dividend by around 10%. 

"2018 was a successful and pivotal year for Comcast. I'm pleased with the strong operational and financial results that we delivered across the company," said CEO Brian Roberts. "We truly became a global company with our acquisition of Sky, and are excited about its future and the potential of our combined company in 2019 and beyond."

Action Alerts PLUS holding Comcast's decline is a little more perplexing considering that the iShares Evolved U.S. Media and Entertainment ETF (IEME) - Get Report and Invesco Dynamic Media ETF (PBS) - Get Report , two of the markets largest media ETFs, are up 0.6% and 0.7%, respectively. 

"I think Comcast is down off investors profit-taking after Wednesday's near 5.50% jump in reaction to the quarterly results. But that doesn't take away from the company's strong earnings result and good cash flow numbers. Plus, the acquisition of Sky looks to be a strong growth asset that expands Comcast's global reach," Action Alerts PLUS senior analyst Jeff Marks told TheStreet Thursday. 

Analysts at Deutsche Bank were bullish on the stock in a note published Thursday, though the firm maintained its $44 price target and buy rating. 

"Comcast reported 4Q results that were above our estimates across all three of its segments - Cable, NBCU and Sky. While nothing in the results changed our thesis or view on the stock, there were some positive and negative implications from incorporating elements of management's guidance into our forecast," analyst Bryan Kraft wrote.