Key Highlights

● Sandisk's rally was a read-through from SK hynix's results.

● SK hynix posted profit up more than sevenfold year over year.

● Sandisk makes NAND flash memory for SSDs and data centers.

● Nvidia was a rare decliner among major chip names.

Sandisk (NASDAQ:SNDK) soared on Wednesday, October 28, ranking among the strongest technology gainers in the S&P 500 after a blowout quarter from SK hynix (NASDAQ:SKHY) reminded investors just how tight the memory market has become.

Sandisk did not report results of its own. The flash-memory maker's rally was a read-through from its larger South Korean peer, according to market data, which tied the move to the memory rally sparked by SK hynix.

A Record Quarter in Seoul

SK hynix posted its first quarter with more than 100 trillion won in revenue, roughly $78.7 billion. Operating profit reached about $62.7 billion, and profit jumped more than sevenfold, according to market reports.

The company also unveiled a shareholder return plan of about 100 trillion won and said it sees the memory shortage lasting into 2030. Its US-listed shares jumped, and South Korea's KOSPI index soared. For Sandisk, which makes NAND flash memory used in solid-state drives, smartphones and data-center storage, that outlook is a powerful tailwind.

Memory Names Lead

Sandisk led a broad memory rally. Micron (NASDAQ:MU) climbed, Seagate (NASDAQ:STX) rose after its quarterly report, and chip-equipment makers Lam Research (NASDAQ:LRCX) and Applied Materials (NASDAQ:AMAT) jumped as investors bet that memory producers will spend more to expand capacity.

The Philadelphia Semiconductor Index rose for a fourth straight session to close at 11,684.00. Nvidia (NASDAQ:NVDA) was a rare decliner among the big chip names.

Riding the AI Build-Out

Demand for memory has been supercharged by artificial intelligence. AI servers need large amounts of high-speed memory to run models, and the data they generate must be stored somewhere. That has pulled flash storage, once a cyclical commodity business, into the center of the AI trade.

Wednesday's other AI headlines reinforced the theme. Vertiv Holdings (NYSE:VRT) rocketed after orders more than doubled, and Oracle (NYSE:ORCL) soared after setting a $225 billion fiscal 2030 revenue target.

What to Watch

The memory rally met a speed bump after the bell. Alphabet (NASDAQ:GOOGL) slid sharply in extended trading after missing profit expectations, and Micron slipped in sympathy. Still, Alphabet raised its 2026 capital spending forecast to between $195 billion and $205 billion, and Microsoft (NASDAQ:MSFT) rose after its Azure cloud business accelerated.

Amazon (NASDAQ:AMZN) reports after Thursday's close, offering another major read on cloud infrastructure spending, and Apple (NASDAQ:AAPL) and Meta (NASDAQ:META) report later this week.