Stock Market Today, Dec. 18: Micron Technology Surges on Record Results and News It Is 'Sold Out'

Micron Technology (NASDAQ:MU), a leading memory and storage chipmaker, closed Thursday at $248.55, up 10.11%. Trading volume reached 63.9 million shares, about 139% above its three-month average of 26.7 million shares. Micron Technology IPO'd in 1984 and has grown 17,528% since its initial public offering.

Today's move followed record fiscal Q1 2026 results and a blowout revenue outlook. Micron beat estimates on both earnings per share and revenue. Investors will be watching how high-bandwidth memory growth might shape Micron’s margins and future cash generation.

How the markets moved today

The S&P 500 (SNPINDEX:^GSPC) rose 0.79% to 6,774, while the Nasdaq Composite (NASDAQINDEX:^IXIC) gained 1.38% to finish at 23,006. Within semiconductor memory manufacturing, major chipmakers rallied alongside Micron as investors reassessed the sector’s earnings power in an AI-driven cycle.

What this means for investors

Micron's earnings surprised markets today, prompting a double-digit price surge and boosting other AI stocks. It reported quarterly revenue of $13.64 billion, up from $8.71 billion for the same period last year.

Business chief Sumit Sadana told investors the company is "sold out." It already has agreements to sell its entire high-bandwidth memory (HBM) supply in 2026. It forecasted HBM revenue would rise from $35 billion in 2025 to around $100 billion in 2028.

Various analysts increased their Micron price targets. Morgan Stanley (NYSE:MS) said it is a top U.S. semiconductor pick and increased its price target from $338 to $350, an upside of over 40%.

Emma Newbery has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.