New York (CNN Business) Transparent braces are a rapidly growing business, and SmileDirectClub plans to cash in with a bigger-than-expected initial public stock offering.

SmileDirectClub has priced its IPO at $23 per share, which is more than expected, ahead of its Thursday debut. The company originally expected to price its shares between $19 and $22.

The stock opened at $20.55 per share, 11% lower than expected. Losses accelerated through the afternoon with shares losing 18% of their value.

SmileDirectClub started five years ago, selling "tight-fitting clear aligners" that act as braces. The product costs $1,895, but it also offers monthly payments for $85 a month over 24 months, which, with a deposit, brings the total price of the aligner to $2,290.

The company is now valued at nearly $9 billion, according to a company press release

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