Activist investor Bill Ackman disclosed a new long position in Starbucks (SBUX) at a conference on Tuesday.

Ackman, who amassed his stake over the last 90 days, owns 15 million shares, valued at around $900 million. He thinks the stock is a double, or as he put it a “Doppio,” a play on the company’s affinity for using Italian in its drink names.

Speaking at Grant’s Fall 2018 Conference at the Plaza Hotel in New York, he called the coffee juggernaut “one of the greatest businesses in the world.” Ackman said he wished that he had bought shares during the 2008 financial crisis when the stock was closer to $5.

According to Ackman, the growth driver is China, where premium coffee is becoming an aspirational product as more Chinese enter the middle class.

“Many Chinese go to Starbucks as the ‘third place’ to hang out,” Ackman said, adding that the company has a “big runway” in China. Starbucks has said that it’s opening a store in China every 15 hours.

Ackman downplayed some of the new competition in China, including Luckin.

“It’s a bit like saying a new hamburger chain opened with McDonald’s,” he said.

As a category, coffee is an attractive growth industry. Ackman noted that it’s “healthy, unlike soda” and it’s also “addicting.”

“This is one of the most dominant companies in the industry that I’ve ever seen,” Ackman said, adding, “This is an extremely dominate business.”

Another trend that makes it an attractive category is that teens are buying coffee more than those of previous generations.

“People drinking coffee is young people and Starbucks will be the biggest beneficiary.”

One of the reasons the stock has been weak is because of the CEO change, with founder Howard Schultz stepping down. Former Juniper Networks CEO Kevin Johnson took the helm at Starbucks in April 2016. Schultz stepped down from the board and his role as chairman on June 26 and said at the time he’d explore a range of options “from philanthropy to public service.”

Another issue dragging the stock has been the slowdown in U.S. same-store sales, which Ackman said is “fixable.” One of the reasons same-store sales in the U.S. have deteriorated is due to competition at both the high and low end.

One way to counteract that trend of slowing sales is the focus on higher end stores through its Reserve Roastery brand. Ackman called these stores “altars” that offer the consumer a great experience with the brand.

Another key opportunity for Starbucks to pick up sales again is food. In particular, he’s upbeat on the Mercato offerings.

Ackman also praised the company for the way it treats its employees, or “partners” as they’re referred to internally. Starbucks offers healthcare to both full-time and part-time employees. The company also offers equity in the form of stock options. Other benefits include college tuition. Ackman noted that Starbucks wouldn’t be threatened by a minimum wage increase.