Shares of Jack Dorsey's Square rocketed to an intraday all-time high of $17.75 Thursday morning, coming close to doubling its initial offering price of $9 a share.
The stock ended the day 14 percent higher after the mobile payment company reported better-than-expected earnings and revenue.
The sharp move marked the stock's best daily performance since its initial public offering little more than a year ago in late 2015, when the stock gained more than 45 percent in one day.
Square reported late Wednesday a loss of 4 cents a share, beating a Thomson Reuters consensus estimate of a 9-cent loss. Revenue also surpassed forecasts, coming in at $452 million for the quarter, compared to the $450 million estimate.
With Thursday's gains, shares are up 90 percent since Square's IPO. CEO Dorsey also runs social media company Twitter.
—CNBC's Christine Wang contributed to this report.