Could Nvidia extend its enormous gain?Nvidia's (NVDA 2.57%) shares are on fire -- but this isn't a short-term phenomenon. The chip designer's stock has been on the rise for a few years. It took off in 2020, and since that time, it's soared more than 1,600%.Investors have piled into the stock on optimism about the company's position in artificial intelligence (AI), a market forecast to grow in the double digits to more than $1 trillion by the end of the decade. Today, Nvidia is the world's AI chip leader, wi ...