Lululemon Athletica will join the S&P 500 index before the stock market opens on October 18.
Stocks added to the S&P 500 and other benchmarks often see a solid near-term boost as investors add their shares to funds that track the major indices.
Lululemon, which went public in 2007, has a market value of around $48 billion.
Earlier this summer, Lululemon lifted its forecast full-year revenues to between $9.51 billion and $9.57 billion following better-than-expected second-quarter earnings compared with muted outlooks from rivals including Nike and Adidas.
The company will replace Activision Blizzard, the gaming company acquired by Microsoft.
