Nvidia (NVDA 0.86%) is unlike any stock we've ever seen. It may be the world's largest company (although it can trade its leadership position with Microsoft (NASDAQ: MSFT) from day to day), but it's growing faster than 99% of companies in the market. There's also plenty of room for further growth, so Nvidia's ascension is far from over. However, I think there is one metric many investors are glancing over that showcases just how much of a screaming buy Nvidia is right now, and investors should be loading up ...