If there were any concerns that Jack Dorsey was planning to leave Twitter (TWTR) , the embattled CEO put them to rest in a single tweet on Tuesday. 

#LoveTwitter https://t.co/fELbw0ska7

— jack (@jack) February 14, 2017

With the hashtag "LoveTwitter," Dorsey tweeted out a link to an SEC filing showing he bought about 426,000 shares of Twitter on the open market this week for roughly $7 million. That increases Dorsey's overall stake in Twitter by about 3%; his ownership now stands at a total of about 15.46 million shares, or roughly 2% of the company's outstanding shares. At the company's current share price of $16.77, those shares would be worth about $259 million.

Shares of Twitter were up about 1.5% on Wednesday afternoon after rising more than 5.8% on Monday and Tuesday. The stock plummeted 12.4% last Thursday following the company's less-than-stellar fourth-quarter results

Dorsey's SEC filing noted that he bought 63,007 shares on Monday for a weighted average price of $15.87, followed by the purchase of 362,991 shares on Tuesday for a weighted average price of $16.52 per share. 

It's the first time Dorsey has purchased Twitter stock since August 2015, when he bought about 31,600 shares. It's also the largest share acquisition by a Twitter executive in almost a full year, going back to when CFO Anthony Noto and executive chairman Omid Kordestani together purchased more than 135,000 shares on Feb. 16, 2016. 

TheStreet's Jim Cramer, co-manager of the Action Alerts PLUS portfolio, said on CNBC's "Mad Dash" segment Wednesday that Dorsey's purchase is "a lot of money" and acts as a sign of confidence for a "revenue-challenged company." 

It might also be the biggest open market purchase of Twitter shares among insiders and executives in the company's history, said CFRA Research analyst Scott Kessler. Many CEOs are granted stock options that must be exercised by a certain date, but Dorsey's purchase was done voluntarily on the open market. 

"You have the most visible, arguably important leader of the company taking his own money and committing it to buy Twitter stock in the open market," Kessler explained. "That says something." 

What it likely says is that Dorsey sees value in Twitter shares at a time when by and large many people don't, Kessler noted. Dorsey could be signaling that Twitter shares have more room to run or he could be trying to appeal to investors whose confidence has recently been shaken. 

Dorsey's seemingly ringing endorsement of Twitter comes as other top executives have dumped a portion of their shares. A number of Twitter insiders sold as much as $103 million in shares across the months of May, June and July in 2015. 

Former Chief Operating Officer Adam Bain sold 68,813 Twitter shares last November, shortly before announcing he would exit the company. Ex-Chief Technology Officer Adam Messinger also sold about 52,000 shares last November, before leaving last December. 

Along with Bain and Messinger, Twitter's vice president of diversity and inclusion Jeffery Siminoff is leaving this month, while its chief human resources officer Renee Atwood left earlier this month. 

Some investors have been calling for Dorsey to step down or be replaced as Twitter's CEO for some time, arguing that his attention is unduly split with the other public company he runs, payments firm Square  (SQ) , but Dorsey's latest move shows that's unlikely to happen -- at least voluntarily. 

"He's not buying the stock because he's planning on exiting in the near term," Kessler added. 

Odeon Capital analyst Jahanara Nissar said the move further indicates that Twitter is definitely not in any takeover crosshairs. Last fall, Disney (DIS) , Alphabet's (GOOGL) Google unit and Salesforce (CRM) were all rumored as possible buyers of the embattled social media site.

"Dorsey buying more shares is a signal that he is committed to stay and that the company is not in any takeover talks right now," Nissar said by email. "Especially after the anemic earnings a few days ago, it's a sign that he is trying to reassure investors and employees that he has conviction in the future stock price."

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