Shares of Signet surged more than 20 percent Thursday after the jewelry retailer reported better-than-expected results and boosted its full-year outlook.

Signet — the owner of Kay Jewelers, Zales and Jared jewelry stores — reported earnings that were more than double estimates and posted revenue well above forecasts, including a 1.7 percent increase in sales at stores open for at least 12 months. Sales at Zales rose 7.1 percent while sales at the Bermuda-based retailer's Piercing Pagoda brand jumped 11.5 percent.

The world's largest diamond retailer also raised its full-year earnings and revenue guidance.

Those results sent Signet's stock surging, with it posting its best day in more than two decades, dating to April 1996. The stock traded as high as $71.07, its highest intraday level since November 2017.

Signet's bullish sales report comes in the wake of a surprise uptick in retail sales last month. Retail sales in the U.S. jumped a half percent last month, and 6.4 percent from a year ago.

Here's what the jewelry retailer reported for the second quarter compared with what Wall Street analysts polled by Thomson Reuters expected: