The Singles Day, or Double 11, is a Chinese shopping holiday that originated as an unofficial holiday for bachelors. The date, November 11 (11/11), was chosen because the number "1" resembles a "bare stick", which is a Chinese slang for a lonely man with no significant others, and four "1"s (the most that can fit into a calendar date if disregarding the year) abstractly refer to the demographic group of single men.
The holiday has ironically also become a popular date to celebrate relationships (to "pair up singles"), with over 4,000 couples being married in Beijing on this date in 2011, compared to an average of 700 a day.
The holiday has become the largest offline and online shopping day in the world, with Alibaba shoppers exceeding 213.5 billion yuan (USD $30.7 billion) in purchase during the 2018 celebration. Rival JD.com hosts an eleven-day shopping festival as well, which garnered USD $19.1 billion, bringing the Chinese total to USD $44.5 billion.
In 2019, Alibaba said that its gross merchandise volume for the whole event came in at 268.4 billion yuan (USD $38.4 billion), an increase of 26 percent from the previous year.
According to en.wikipedia