MKM Partners' Rob Sanderson downgraded Twitter in June 2015 shortly before the stock would be cut in half on disappointing user growth and advertising revenue.
But now he is positive, upgrading the stock to buy from neutral on Friday with a note titled, "Twitter is Here to Stay and Still Has Mass Market Potential."
Sanderson also set a $40 12-month price target on the stock, 27 percent higher than where it closed on Thursday.
"We think execution was sub-par for about three years leading into 2017 and has improved under the return of its co-founder as CEO [Jack Dorsey]," the note stated. "Despite this lengthy execution gap and hefty competition for user time and attention, the company has maintained its position as the go-to source for what's happening in the world."
"We think this reflects the importance, differentiation and 'antifragile' nature of Twitter. It increasingly appears that Twitter is here to stay," he added.
Shares of Twitter jumped more than 3 percent in premarket trading Friday on the upgrade as the analyst also noted that he believes advertisers are allocating more to the social media platform.
Sanderson believes the recent weakness related to Facebook's Cambridge Analytica privacy issue is misplaced by investors.
"The stock has traded down by 15% (NASDAQ down 3%) in sympathy with the user data scandal at FB," Sanderson wrote. "While TWTR has a high margin and high growth data business, we think the company is relatively insulated from similar scrutiny as all content is posted by users in a purely public forum for anyone to see."