Thousands of Hong Kongers are flocking to a Costco store in mainland China. Here's why.

• Costco opened a new store in Shenzhen, China, in January.
• Thousands of Hong Kong residents have since flocked to the store in search of discounts.
• More than 15,000 Hong Kong members have signed up for the store, Costco's CFO said, per Bloomberg.

A new Costco store caused quite a stir when it opened its doors in Shenzhen, China, last month, with tens of thousands of people queuing for hours to enter, Bloomberg reported.

Among the droves of discount shoppers were many Hong Kongers, enticed across the boundary with mainland China by the store's discount prices.