MANCHESTER, United Kingdom — British online fashion retailer Boohoo Group Plc is leaving rival Asos Plc in the dust, consolidating its position as the industry's new market darling.

Shares of Boohoo rose to a record on Thursday after the company raised its annual sales outlook, pushing its market value to about £3.3 billion ($4 billion). It’s the biggest company on AIM, London Stock Exchange’s junior market for growth companies. Asos, which was worth £6.5 billion as recently as March 2018, now has a value of only about £2 billion.

Asos shares have lost more than a third of their value since the London-based company reduced its sales outlook in December. It disappointed the market again in July after saying a move to new technology at US and European warehouses was taking longer than expected. Boohoo, on the other hand, increased its full-year sales growth forecast on Thursday, a month after buying British brands Karen Millen and Coast.

“Boohoo’s sales growth is much stronger, which reflects both its smaller size and what seems to be more effective marketing and the multi-brand approach,” said Charles Allen, an analyst at Bloomberg Intelligence. “Boohoo currently has a more resilient business model while Asos has stumbled in building out its automated warehouse infrastructure.”

Boohoo shares jumped 15 percent as of 10:32 am in London, while Asos added 3.8 percent.

By Lisa Pham; editor: Beth Mellor and Namitha Jagadeesh, Jon Menon.