Update Wednesday, 2:15 p.m. ET: 

Shares of Warby Parker opened on their first day of trading at $54.05, well above their reference price. They dipped a bit after that and were hovering at about $53.83 as of midday on Wednesday. You can follow the stock here.

Original post:

Eyewear brand Warby Parker is going public today. However, instead of going public via the traditional initial public offering (IPO) route, Warby Parker is instead debuting its shares via a direct listing. Here’s what you need to know:

• What is Warby Parker? Warby Parker is an eyewear brand that sells prescription frames and sunglasses. The company was founded in 2010 and sells its eyewear online and in retail stores. Warby Parker is known for its “Home Try-On” program, which lets online customers choose five frames that are shipped to them, with the customer keeping the best fit and sending the rest back.
• What ticker will Warby Parker trade under? Warby Parker shares will trade under the ticker symbol WRBY.
• What exchange will Warby Parker trade on? Warby Parker will trade on the New York Stock Exchange (NYSE).
• How is a direct listing different than an IPO? In an IPO, the company creates new shares and those are sold to the public. But in a direct listing, no new shares are created. Instead, the company’s existing shareholders (earlier investors and employees) put up their shares for sale.
• What is WRBY’s starting price per share? Since it’s not an IPO, there is no fixed price per share at which WRBY will begin trading. (In an IPO, the bank underwriters choose the starting share price.) Instead, direct listings have a reference price for the stock. However, the reference price is mostly meaningless as shares can begin trading well above or below any stated reference price. The reference price for WRBY is $40.
• How many WRBY shares are available? For its direct listing today, roughly 92.5 million shares of common stock will be available for purchase.

Update: This article has been updated to reflect the announcement Warby Parker made after filing its prospectus, which stated that 77.7 million shares of common stock will be available for purchase. In a press release following the prospectus, Warby Parker announced 92.5 million shares of Class A common stock will be available for its public offering.