One of last week's biggest winners was Twitter (NYSE:TWTR), soaring 10.95% after a pair of analyst upgrades. Morgan Stanley's Brian Nowak is no longer bearish on the stock. Rob Sanderson at MKM Partners is now bullish on the social media giant. 

The timing of the upgrades is important. Twitter reports fresh financials on Wednesday morning. Two Wall Street pros lifting their opinions on the stock just days ahead of the announcement of Twitter's first-quarter report is a good sign. Nowak and Sanderson have to feel strongly about this being a blowout report or else they will come out looking silly for juicing up their ratings. 

Twitter mascot in a blue background.

Image source: Twitter.   

Tweet dreams

Morgan Stanley's Nowak kicked off the back-to-back upgrades last week. He boosted his rating from underweight to equal weight after recent checks with advertisers show them upbeat about Twitter's ad business. He is boosting his Twitter owned and operated ad revenue estimates for this year as well as 2019, encouraged by momentum and upcoming traffic-boosting event catalysts including this summer's FIFA World Cup and the fall's midterm elections. 

Nowak's officially neutral now. He's bumping his price target from $28 to $29, essentially where the stock was at the time of the upgrade -- but a price goal that is now lower than where the stock rests after last week's pop.

Sanderson at MKM Partners is more optimistic on the shares, boosting his rating from neutral to buy. His new $40 price target leaves 25% of upside even after last week's big gain. He is encouraged by Twitter's turnaround efforts and rebounding user growth. Twitter has now come through with five quarters in a row of double-digit growth in daily active users. 

The playing field is now set for Twitter to report its first-quarter results ahead of Wednesday's market open. Analysts see revenue rising 10% to $605.3 million, checking in with a profit of $0.11 a share. It earned just $0.07 a share a year earlier. 

The shares will be volatile on Wednesday, and not just because the weight of earnings season is upon the reinvigorated dot-com darling. The stock has posted double-digit percentage moves in each of the past five earnings weeks, including a 22% surge last time out. The stock finds itself a 15% gain away from revisiting last month's two-year high, a high-water mark that it can take out with another big week.  

Rick Munarriz owns shares of Twitter. The Motley Fool owns shares of and recommends Twitter. The Motley Fool has a disclosure policy.