Carvana shares are down almost 10% this morning even as the online used-car retailer delivered another quarter of impressive looking headline results, highlighting growing skepticism that its financial rebound may be outpacing the realities of a shaky auto market.

Revenue jumped to $5.65 billion from $3.66 billion a year earlier, powered by a 44% increase in retail units sold to 155,941, according to Bloomberg. Net income rose to $263 million, or $1.03 per share, compared with $148 million, or 64 cents, a year ago. Adjusted earnings hit $1.50 per share, well ahead of expectations, while adjusted EBITDA climbed to $637 million. The company projected fourth-quarter retail unit sales above 150,000 vehicles.

CEO Ernie Garcia celebrated the scale of the recovery, telling shareholders: "Not only is this growth happening at the same time we are producing margins higher than have ever been reported by any other automotive retailer, but it is also happening at a very significant scale."