"I'm coming to the conclusion that Twitter is a feature," he said during Thursday afternoon's "Fast Money Halftime Report" on CNBC. "It can't get more promoted than it is. It's part of the psyche of the election, you hear about it every day and yet they can't seem to monetize it."
O'Leary added that the 32 small-cap privately held companies in what he called his "Shark Tank Index" are falling out of love with the social media platform.
"They are now using Snapchat, Instagram, LinkedIn (LNKD), and this new feature Facebook (FB) Live. So when I talk to those 32 CEOs and ask what's up with Twitter, they cite no growth," he noted.
O'Leary expects Twitter's stock to decease to $12 a share shortly.
"There is no growth; they have not been able to use it in a way to monetize it in consumer goods and services. So maybe this thing gets attached to something as a newsfeed, but we already heard that story. I don't know what it takes to turn it around," he explained.
Twitter posted better-than-anticipated 2016 third-quarter results before the market open on Thursday. The social media site reported earnings of 13 cents per share on revenue of $616 million. Analysts were expecting earnings of 9 cents per share on revenue of $605.8 million.
Shares of Twitter were higher in early afternoon trading on Thursday.
Separately, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.
The team rates Twitter as a Hold with a ratings score of C-. The company's strengths can be seen in multiple areas, such as its impressive record of earnings per share growth, robust revenue growth and good cash flow from operations. However, as a counter to these strengths, the team finds that the stock has had a generally disappointing performance in the past year.
You can view the full analysis from the report here: TWTR