Micron Turned $10,000 Into About $130,000 in 5 Years. Most of It Came in the Past 12 Months.

A year ago, a $10,000 investment in Micron Technology (NASDAQ:MU), bought at the stock's Sept. 15, 2021, closing price of $73.82, was worth about $21,500.

That was a solid four-year result. Not only had the money more than doubled, but it had also outpaced the S&P 500 (SNPINDEX:^GSPC), which rose about 47% over those four years and about 69% over the entire five.

Then came year five. Shares have risen from about $159 in September 2025 to about $975 as I write this, a more than sixfold move that brings the five-year total to about $130,000 -- about 13 times the initial stake. (That reflects price alone. Micron's modest dividend, started in 2021, would add a little more if reinvested.)

Gains that arrive that quickly typically have a particular cause, and Micron's does: the price of memory. I'd say the cause deserves as much focus as the payoff, because memory prices move in cycles -- and this stock went through both halves of one within the five years.

Image source: Micron.

A back-loaded five years

The five-year number masks how bumpy the ride was. One year into the holding period, in late September 2022, Micron's stock closed under $49. The $10,000 had dropped to about $6,600.

The business, of course, followed the stock lower. Memory prices were falling, and in fiscal 2023, Micron's revenue fell by about half, to $15.5 billion from fiscal 2022's $30.8 billion. The company lost $5.83 billion that year.

The rebound that followed took the investment back to about $21,500 by this time last year. Zooming out, almost the whole payoff was in the final 12 months.

Memory prices did most of the work

What shifted was the price of memory, bid up by demand from artificial intelligence (AI) data centers. In its most recent quarterly filing, Micron said AI-driven growth has accelerated demand for memory and storage more quickly than the industry can increase supply.

Micron's quarterly revenue rose across fiscal 2026 -- $13.6 billion in the first quarter, $23.9 billion in the second, and $41.5 billion in the third, the quarter that ended May 28, 2026. The steps kept getting bigger, and the third-quarter figure was up 346% year over year. Net income totaled $28.2 billion for the quarter, which means Micron earned nearly five times as much in three months as it earned in all of fiscal 2021 ($5.9 billion), the fiscal year that ended not long before the $10,000 went in. And its non-GAAP (adjusted) gross margin reached 84.9%. Twelve months before that, it was 39%.

Very little of this came from selling more memory. In the same filing, Micron reported the quarter's DRAM sales increased 343% year over year, with average selling prices rising about 260% while shipment volumes grew a little over 20%. So the company sold a bit more memory at several times the price.

How long can earnings at this level last?

Management maintains the boom has staying power. Along with the fiscal third-quarter results, Micron announced a set of multi-year Strategic Customer Agreements, deals under which big customers lock in memory supply for years to come. CEO Sanjay Mehrotra said the company thinks the agreements "will significantly enhance the durability and predictability of Micron's strong financial performance."

The market, though, looks less persuaded. The stock currently trades at about 6 times what Micron is expected to earn in the fiscal year that began this month (fiscal 2027). That's the type of earnings multiple investors pay when they expect profits to decline. The September 2021 buyer, by contrast, paid about 9.5 times what Micron would later earn in fiscal 2022.

Notably, the stock itself already shows some of that skepticism, trading about 22% below its 52-week high of $1,255.

In my view, however, Micron's own history argues against forever. The last boom peaked in fiscal 2022, revenue fell by about half within a year, and the $5.83 billion loss came at the bottom.

Granted, the new agreements might make this cycle longer and flatter than the last one. But they have not been tested by falling prices yet.

If I owned the stock, I'd keep holding it. And a business earning at this rate isn't one I'd sell simply because memory is cyclical.

But most of that $130,000 came from a single exceptional year, and a buyer around $975 is, I think, risking overpaying.

Daniel Sparks and his clients do not have positions in any of the stocks mentioned. The Motley Fool has positions in and recommends Micron Technology. The Motley Fool has a disclosure policy.