BEIJING, China — Alibaba Group Holding Ltd. posted $1 billion (6.81 billion yuan) of sales within the first five minutes of its Singles' Day shopathon, a 24-hour event that may offer clues on the health of the Chinese economy and its largest online retailer.

Investors are keeping a close eye on the annual Nov. 11 spending blitz that dwarfs Black Friday and Cyber Monday in the US, to see if Alibaba can reprise the 60 percent leap in transactions to 91.2 billion yuan it managed last year. The e-commerce giant again turned up the star-wattage for 2016, enlisting Hollywood actress Scarlett Johansson, sports celebrity David Beckham, basketball legend Kobe Bryant and pop-rock band One Republic to headline a pre-sale gala and drum up international attention.

Pioneered by Alibaba in 2009 and since replicated by rivals including JD.com Inc., Singles’ Day has become somewhat of a barometer of Chinese consumer sentiment. Executives have set the bar high, confidently predicting another record-breaking endeavour at a time when the economy’s growing at its slowest pace in a quarter-century and a weakening yuan may curb enthusiasm for foreign wares.

“Alibaba will likely break another Singles’ Day sales record this year as bargain-seeking Chinese consumers again flex their spending muscle and shrug off any concerns there may be about China’s slowing economy,” said Andria Cheng, an eMarketer analyst. “Many foreign brands, with and without local China presence, will use this shopping event to further raise their brand profile with Chinese consumers.”

Singles’ Day was invented by college students in the 1990s as a counter to Valentine’s Day, according to the Communist Party-owned People’s Daily. Written numerically, Nov. 11 is reminiscent of “bare branches,” a local expression for bachelors and spinsters. It has since morphed into a consumption phenomenon involving months of planning, millions of logistics and technology personnel, and a nationwide cascade of ads and promotions.

Some 11,000 brands will be hawking their products on the day. Alibaba is touting a virtual reality service to let Chinese buy from Macy’s in New York and Tokyo’s Otaku Mode. It’s added live-streaming to its sites and even a location-based Pokemon Go-like mobile game to try and drum up interest.

"Consumer behaviour is changing," Alibaba chief executive officer Daniel Zhang said during the gala. "Shopping has become entertainment."

Alibaba’s US-traded shares fell as much as 4.6 percent Thursday due to concerns about how Donald Trump’s presidency could affect the company’s overseas expansion.

For the first six years, results were tabulated in Alibaba’s hometown of Hangzhou in eastern China. This year, it relocated its command centre to the southern city of Shenzhen just across the border from Hong Kong, to try and capture international attention. Ma, who aims to get half the company’s revenue from beyond China by around 2025, has said that he wants to introduce the shopping festival to the US and UK.

Last year, a third of buyers made purchases abroad during the event — Nike sneakers and Levi’s jeans were among the hotter items. Global retail e-commerce is expected to grow by 24 percent to $1.91 trillion in transactions this year, according to eMarketer. In China alone, that number will increase by 36 percent to $899 billion, it said.

Alibaba’s event however has drawn controversy around how it accounts for purchases, or gross merchandise volume. The US Securities and Exchange Commission has been looking into data from last year’s promotion, responding in part to concerns that the total may include sales faked by third-party merchants or transactions that haven’t been paid for. Vice Chairman Joseph Tsai has said the company is cooperating with the regulator, sharing facts in an investigation it voluntarily disclosed.

Allegations of numbers-inflation have surfaced locally as well. On Tuesday, the State Administration for Industry and Commerce said it had summoned the largest online retailers — including Alibaba, JD, Tencent Holdings Ltd. and Amazon.com Inc. — to a meeting, warning them against inflating sales, touting fake goods or predatory tactics on the day.

“There’s a lot of fuzziness into that number,” Paul Sweeney, an analyst with Bloomberg Intelligence, told Bloomberg Television. But “most investors look at the gross merchandise value that they report more for the directional tone that they set.”

By Tom Mackenzie and Lulu Yilun; editors: Robert Fenner, Edwin Chan and Molly Schuetz.