Yu’E Bao, the world’s biggest money-market fund, still has potential to grow more even after it expanded at the fastest half-year pace in three years in the first six months of 2017, according to Fitch Ratings.

The Chinese fund is sold on the mobile-payment platform Alipay, offered by Alibaba Group Holding Ltd.’s financial affiliate, which is controlled by Jack Ma. The billionaire founder of Alibaba has promoted Alipay for everything from grocery shopping to settling restaurant bills. That’s spurred growth of Yu’E Bao, which gives users a way to stash away savings with no minimum investment or time frame.

Yu’E Bao has 1.4 trillion yuan ($210 billion) of assets under management, accounting for about 28 percent of China’s money-market funds. It has beaten the average returns for money-market funds in the nation for much of this year, further boosting its allure, according to Fitch analyst Huang Li.

“People are more willing to use Alipay to make payments and its customers have a high level of loyalty,” Huang said in an interview in Shanghai. “Alipay is getting more and more convenient. If the money-market fund offered on Alipay can offer higher yields, it will certainly attract more investors.”

Tianhong Asset Management Co., which is majority owned by the Ant Financial affiliate and manages Yu’E Bao funds, declined to comment on growth prospects. Ant Financial is formally known as Zhejiang Ant Small & Micro Financial Services Group.

Increasingly Attractive

Chinese money-market funds have gotten an extra boost this year, after the government sparked an increase in short-term bond yields as it cracked down on leverage in the financial system.

The seven-day annualized yield offered by Yu’E Bao has averaged 3.87 percent in 2017, according to Bloomberg-compiled data. That compares with 3.74 percent on all local money-market funds this year, according to research firm Howbuy.

The flood of money into Yu’E Bao may have prompted Tianhong Asset to seek ways to control risks, said Fitch’s Huang. The company lowered the investment cap in the fund to 100,000 yuan earlier this month.

But the rule change may not alter the growth trend, said Huang.

“On average, customers invest about 4,000 yuan,” she said. “Assuming every customer added just another 1,000 yuan, it would be a 25 percent increase.”

The fund had 324 million investors as of Dec. 31, according to Tianhong. More than 99 percent of the fund’s shares were held by individual investors.

Recent figures underscore how Yu’E Bao is driving expansion in the industry. Its assets under management rose by 623 billion yuan in the first half of this year. That accounted for the bulk of the 822 billion yuan expansion in all Chinese money-market funds, according to the Asset Management Association of China.