Nvidia's gross margin disappointed last quarter. That could be an area of future focus.Shares of Nvidia (NVDA 1.51%) sold off after the company's recent earnings report and are now down about 11% from their all-time high.Nvidia is still posting excellent growth, with revenue up 122% in the quarter, ahead of analyst expectations. But with the stock exceeding a $3 trillion market cap and expectations extremely high, Nvidia sold off anyway following the release.One reasons could be concern over the company's g ...