Carvana, the online used-car retailer that last week was the target of a short-selling research report, got its first broker upgrade since then which says the controversy has sparked a buying opportunity.

Acknowledging that there is skepticism surrounding its business model and ability to sustain profitability targets, RBC Capital joins the growing list of bulls in support of Carvana, raising its rating on the stock to Outperform from Sector Perform on the upside potential to retail unit estimates and a clearer path to durable free cash flow.