Shopify Inc. shares fell over 11 percent on Wednesday after short-seller Citron Research said the stock of the Canadian provider of online retailing software was overvalued, according to traders and analysts.

Citron’s Andrew Left criticized the company’s marketing practices in a report, saying that it used a network of affiliates to promote its services.

He set a price target of $60. The stock, which had been trading near all-time highs recently, was trading at $103.7 in New York and C$129.5 in Toronto.

Representatives with 13-year-old Shopify, which has a market cap of over $11 billion and has yet to turn a profit, could not be immediately reached by phone or email for comment.

In the past, Shopify has said partners are an important part of its business, and while it “can not expect every single merchant to succeed, we are confident that Shopify gives merchants the best chance at success.”

In its last quarterly report, it said it has more than half a million merchants using its software, including major brands like Visa Inc (V.N) and BuzzFeed.

Trading volume was about five times its 90-day average in the United States and about double in Toronto.