Shopify is dismissing comments by U.S. short seller Andrew Left that the Ottawa-based e-commerce company has an “unholy alliance” with Facebook that could cause its stock to plunge once the social media giant decides to “take away Shopify’s punchbowl.”

In a note titled “Shopify has a BIG Facebook Problem!” Left’s Citron Research on Monday alleged “Shopify and Facebook have been in an unholy alliance for years - in which Facebook has shared your personal information with Shopify sponsored/supported opportunists.”

“We will prove that the growth engine of [Shopify] might come to an abrupt halt with revised Facebook privacy guidelines,” wrote Citron in its report.

The comments caused Shopify’s shares to fall more than three per cent.

Shopify (SHOP.TO) did respond to Left’s assertion later on Monday, saying the company’s business model and the success of its users is not tied to Facebook’s data practices.

“It's incorrect to say that our merchants' success is tied to Facebook and its data,” Shopify said in a statement emailed to BNN. “It's similarly incorrect to say that our company's success is based on our Facebook advertising."

Facebook’s reputation has come under fire and the company’s shares have dropped more than nine per cent over the past week in the wake of the Cambridge Analytica scandal.

This is not the first time Shopify has been targeted by Left. In October, the short seller attacked the company’s business model, describing it as “dirtier than Herbalife.” Shopify CEO Tobias Lutke called those claims "preposterous."

Lutke defended his company again from Left’s latest allegations on Monday, pointing out in tweets that the short seller’s report praises Shopify for its “best in class ecommerce solutions.”

Our 600,000+ entrepreneurs can sell on any channel they want to. If their customers want to buy via carrier pigeon, we’ll build a channel for that too. The health of any individual channel has little effect on the overall platform. Demand migrates.

— Tobi Lütke (@tobi) March 26, 2018