Nvidia is a better AI growth stock buy than Micron right now, because despite Micron's steeper recent gains, Nvidia offers a lower valuation and broader product opportunities ahead.

What happened: A comparison of the two chip makers finds that Micron has soared more than 240% this year, while Nvidia has added 9% as of the June 11 market close. Micron trades for 16x forward earnings estimates, while Nvidia trades for 22x.

Why it matters: Both companies have climbed more than 1,000% over the past five years because they supply critical hardware for AI—Nvidia provides graphics processing units (GPUs, the chips that power AI model training and inference), and Micron provides memory and storage. Micron has recently reported record revenue, gross margin, earnings per share, and free cash flow, with demand so strong that the company is unable to serve 100% of its customers' needs. However, Micron's valuation has increased this year while Nvidia's has fallen, suggesting Micron could be heading for a pullback.

What to watch: Nvidia is entering the central processing unit (CPU) market this fall with its first-ever stand-alone CPU and a new superchip, which may set it on track for leadership in the $200 billion（約32兆円） CPU market. Micron forecasts third-quarter revenue of $33.5 billion（約5.4兆円）, a record high, and predicts free cash flow will roughly double sequentially in that period.