SanDisk Surges Up to 11% After S&P 100 Addition Announced, Boosted by $14 Billion Buyback and AI Rally

SanDisk shares climbed as much as 11% on Friday, September 18, closing out a session in which the stock was among the biggest movers in the market. The primary catalyst was the announcement that SanDisk will be added to the S&P 100 on September 21, a milestone that typically triggers forced buying from index funds and ETFs tracking the index.

The rally also drew support from a broader AI-related stock advance, with SanDisk gaining 1.6% in premarket trading alongside Intel, which rose 2.3%, and Micron Technology, which added 1.1%. The company separately announced a $14 billion share repurchase program following $4.5 billion in buybacks executed during the fourth quarter, a scale that attracted attention from investors including commentary tied to Warren Buffett.

Options activity in SNDK surged on the day, with Jim Cramer flagging a "boatload" of bullish options buying in SanDisk alongside Micron and Intel. The stock hit an intraday level of roughly $1,713 in morning trading, up about 6% at that point, before extending gains to close the session up approximately 11% according to Seeking Alpha. Western Digital rose 3% and Micron ticked modestly higher, but SanDisk ran well ahead of every other name in the memory and storage group.

One headwind flagged by analysts was the emergence of a Chinese DRAM giant entering the flash memory market to compete with Samsung and SanDisk, a development that Benzinga noted could present future competitive pressure for both SanDisk and Micron. Despite that concern, the index inclusion and buyback momentum kept buyers firmly in control on the day.