PayPal (PYPL) - Get Report announced plans on Wednesday afternoon to acquire Honey, a tech platform for shopping and rewards. 

The payments giant agreed to acquire Honey for $4 billion, PayPal said in a press release. Shares of PayPal were down 2% in after-hours trading after the deal was announced. 

The acquisition is aimed at helping merchants who use PayPal, and is also intended to boost adoption of Honey's shopping tools among consumers who use PayPal and Venmo, the company said. Venmo has more than 275 million active consumer accounts, while PayPal has 24 million merchant accounts. 

"Honey is amongst the most transformative acquisitions in PayPal's history. It provides a broad portfolio of services to simplify the consumer shopping experience, while at the same time making it more affordable and rewarding," said Dan Schulman, PayPal's president and CEO, in a statement. "The combination of Honey's complementary consumer products with our platform will significantly enhance our ability to drive engagement and play a more meaningful role in the daily lives of our consumers.

PayPal shares are up 21% year to date.