H&M feted the impeding launch of its much-anticipated Alexander Wang collaboration with a star-studded fashion show in Harlem last night. The range, a “Theory of Gym,” marries athletic wear with streetwear, creating a decidedly sporty mélange of bodycon dresses, jerseys, sweatpants and more. Wang is a favorite designer of the celeb set, so it comes as no surprise that several turned out to support the designer in his latest endeavor. Stylish guests included Jessica Chastain, Solange Knowles, Kate Mara, Eddie Redmayne, Justin Theroux and Dakota Fanning. Of course, the Wang-outfitted set was looking particularly fly last night in the designer’s wares for H&M as well as looks from Wang’s personal brands. Take a look through the slideshow to see all the fabulous looks.