Nvidia is holding the stock, but that doesn't necessarily make it a terrific investment for everyday investors. Shares of Nano-X Imaging (NNOX -1.18%) are down about 53% over the past 12 months, and it's not hard to understand why. The company generated a lot of buzz when it earned Food and Drug Administration (FDA) clearance to market the Nanox.ARC a little over a year ago, but sales haven't grown. Nanox.ARC's U.S. launch isn't proceeding as quickly as investors had hoped, but some investors were encourage ...