Most of Wall Street is gushing over Netflix shares after the company crushed fourth-quarter subscriber expectations, but one analyst says it is time for investors to take some profits.

Buckingham Research Group lowered its rating for Netflix shares to neutral from buy, citing concerns over the company's spending on content to boost profit down the road.

"We are confident in Netflix's position as a global streaming leader with new entrants like Disney more apt to be complements than replacements," analyst Matthew Harrigan wrote in a note to clients Tuesday. "Nonetheless, continued share momentum depends on market confidence that NFLX's guided $3.0-4.0B in negative 2018 free cash flow will generate superior investment returns."

Netflix said it added 8.3 million subscribers in the fourth quarter compared with expectations for 6.4 million.