Amazon just surged more than 2%, leading gains in the S&P 500 after a 'record-breaking' holiday season

• Amazon gained more than 2% in early trading Thursday after announcing "record-breaking" holiday sales.
• The e-commerce company's stock surge was the largest gain in the S&P 500 index Thursday.
• Online sales overall hit fresh highs this holiday season, according to a Thursday report from Mastercard.
• Watch Amazon trade live on Markets Insider.

Shares of Amazon rose more than 2% in intraday trading Thursday, the largest gain in the S&P 500 index, after the company announced that it saw a "record-breaking" holiday season.

The e-commerce company said that "billions of items were purchased" along with "tens of millions of Amazon devices" worldwide during the holiday season. As many as 5 million people signed up for a Prime membership, and independent third-party sellers also surpassed a billion items sold, the company said in a press release. Amazon didn't give further details about holiday sales.

Even though the holiday season was shorter than usual this year, online sales overall hit fresh highs, according to a Thursday report from Mastercard. E-commerce sales made up 15% of all holiday revenue, giving retailers a needed end-of-year boost - the holiday season accounts for about a fifth of US retailers' yearly revenue, Bloomberg reported, citing the National Retail Federation.

Online sales were also a win for department stores that have struggled to drive traffic to brick-and-mortar locations this year. While in-store sales dipped 1.8% from a year ago, online sales at department stores surged nearly 7% this holiday season. Shares of department stores such as Macy's, Nordstrom, and JCPenney advanced in trading Thursday.

Two of Amazon's biggest competitors, big-box chains Target and Walmart, were down slightly in early trading Thursday.

Amazon has gained 20% year-to-date through Tuesday's close.