Tomorrow is Singles' Day in China, the biggest shopping day of the year. Alibaba, China's largest e-commerce platform, is already aglow with good news. Last week it said that revenue for the three months to October reached $8.3bn, a 61% rise on the same period last year, as Alibaba's troves of consumer data attracted more advertisers. The company will capture 35% of China's digital ad spending this year, up from 30% in 2016, according to eMarketer, a consultancy. With Singles' Day looming, Alibaba looks set to surpass last year's sales of nearly $18bn. More than 140,000 brands, and hundreds of millions of consumers, will participate; more than 3m warehouse workers and couriers are poised to deliver packages. Shorting Alibaba's stock has become a common way for investors to hedge against a downturn in China's economy. This year that has been a bad bet: the company's share price has more than doubled since January.