Mark Cuban, the billionaire investor and owner of the Dallas Mavericks basketball team, is buying Netflix Inc (NFLX.O) shares because he considers the video streaming company to be an acquisition target.

"I'm buying NFLX stock ... Someone will try to buy them," Cuban tweeted on Friday.

Cuban told cable television network CNBC he bought over 50,000 Netflix shares.

"Now, I'm effectively long, I don't even know the total number, but it's a lot more than 50,000 shares," Cuban told CNBC.

When asked if he had a price target on Netflix's shares, he said: "My target is to never sell it."

Cuban told CNBC it would be "almost a no-brainer" for a major technology company to buy Netflix, given the company's cheap stock price and strong content. He cited Apple Inc (AAPL.O), Google Inc (GOOGL.O), Facebook Inc (FB.O) and Verizon Communications Inc (VZ.N) as examples of potential buyers.

The shares of Los Gatos, California-based Netflix were down around 3.3 percent at $349.52 in afternoon trading on the Nasdaq. The shares traded earlier as low as $341.50, down 5.6 percent, after Goldman Sachs slashed its price target on the stock to $450 from $550, citing slower-than-expected new subscriber growth in the third quarter.

The company's shares plunged 25 percent to $333.53 in after-hours trading Wednesday after the company reported it had signed up fewer video streaming subscribers than forecast for the third quarter.