Asos co-founder Nick Robertson has sold 300,000 shares in the business, netting more than £15.5m.
Robertson, who stepped down from his role as chief executive in September 2015, still holds 6.2% of the company’s issued share capital following the transaction.
Asos’ market cap stands at £4.3bn.
The sell-off comes less than a year after Robertson sold £46m shares to reportedly fund his divorce settlement.
Robertson was reportedly ordered earlier this year to hand over around £70m of his £220m fortune to his ex-wife, Janine, after a public trial in the high court.
It came after the couple allegedly failed to agree on the division of shares and property owned by Robertson.
Asos continued its stellar run over Christmas, with UK sales up 18% and international sales soaring 52%.