Shein and Temu’s battle for US bargain shoppers is getting nasty. Here’s what you need to know.

The lawsuit, filed Friday in Massachusetts federal court, is a dramatic escalation of a contentious legal battle the two fast fashion upstarts have been embroiled in for months. It follows another complaint from Shein, which sued Temu in December for allegedly mobilizing social media influencers to disparage Shein online. In its new suit, Temu claims that Shein has “engaged in a campaign of threats, intimidation, false assertions of infringement, and attempts to impose baseless punitive fines” on apparel makers thought to be working with Temu. Shein has also “forced” exclusivity deals on clothing manufacturers to prevent them from working with Temu, the complaint states. Consumers holding Shein shopping bags in Paris in May. Tomas Stevens/Abaca/Sipa/AP Both companies originated in China and made their names as online retailers specializing in a supersonic version of fast fashion, defined as the rapid design and production of cheap goods that respond to fleeting trends. In some ways, they’re beating industry stalwarts like Zara and H&M (HNNMY) at their own game, by making items more quickly and being more digitally savvy with customers. Shein overtook the two giants in US market share during the pandemic, while Temu has clinched a strong position since its launch last year, according to analytics firm Bloomberg Second Measure. However, the new litigation illustrates how the race is heating up on an emerging industry battlefield. “This shows how competitive the environment is getting,” said Michael Felice, a partner in Kearney’s communications, media and technology practice. A new ‘war’ In its lawsuit filed last week, Temu claimed its recent entry United States, US, on Friday, Oct. 28, 2022. Shein, the online retailer that has turbocharged the global fast-fashion industry, is planning to deepen its foothold in the US as its sales to American shoppers continue to soar, the Wall Street Journal reports. Stephanie Keith/Bloomberg/Getty Images ‘Too good to be true?’ As Shein and Temu take off Temu has sued Shein in the United States, accusing its rival violating antitrust laws Hong Kong— has sued Chinese competitorin in the United, alleging it violate anticompetitive conduct and other illegal behavior such forcing suppliers not work or do business with Temus smaller rival. The lawsuit was filed late Thursday in Massachusetts federal court, and comes after Shein sued Temus smaller rival in December for allegedly using social media influencers to disparage Sheis online. The two companies are both part of PDD, one of the world’s