Micron and Sandisk shares are phenomenally 'overbought.' Are memory stocks flying too close to the sun?

By Christine Ji

Booming AI demand has sent Micron and Sandisk shares far into overbought territory, but historic hardware backlogs are sustaining a rally

Both Micron and Sandisk have sold out of their 2026 production capacity.

Memory-chip makers like Micron Technology and Sandisk have been some of the biggest winners of the artificial-intelligence build-out as their shares continue to skyrocket.

The rally is causing momentum indicators to flash signals that could signify a heavily crowded trade ripe for a correction. Shares of Micron (MU) have surged 275% in 2026 and nearly 830% in the past year, sending the stock's trailing 14-month Relative Strength Index to 90.98 - its highest level since September 1995, according to Dow Jones Market Data. The pattern was initially pointed out by the account @Barchart in a Sunday X post.

Sandisk shares (SNDK) have staged an even bigger rally, rising 788% this year and 4,860% in the past 12 months. The flash memory and storage stock has a 14-month RSI of 98.96, according to Dow Jones Market Data.

Traders use the RSI as a technical momentum indicator to measure the speed and momentum of recent price changes. The RSI is measured on a scale of 0 to 100. A stock with an RSI of 70 is usually considered overbought, meaning that the price has risen very fast.

An RSI above 90 is an incredibly rare threshold, indicating that the total magnitude of the security's upward moves across the trailing 14-period window is nine times greater than its downward moves.

Read: Micron bulls are getting even more optimistic about memory trends as earnings draw closer

An overbought RSI doesn't guarantee a selloff. It's more of an indication that a stock has seen incredible upward momentum. Still, Micron and Sandisk have historically been cyclical companies, defined by boom-and-bust cycles of demand surges and ensuing oversupply.

Shares of Micron and Sandisk could very well sustain their upward momentum, and many on Wall Street have said the memory providers will continue to benefit as Big Tech companies continue to increase their AI capital expenditures. Bulls argue that AI has structurally elevated demand for memory and storage solutions, leading to long-term purchase agreements and more predictable revenue streams for Sandisk and Micron.

Micron has completely sold out its 2026 production capacity for high-bandwidth memory. Investors are eagerly awaiting Micron's fiscal third-quarter financial results on June 24. On its previous earnings call, Micron shared that demand has escalated so rapidly that it's unlikely that 2027 supply will improve.

Sandisk is similarly sold out of its production capacity for 2026. The company has been utilizing long-contracts with quarterly volume commitments and prepayments.

"We think this type of contract fundamentally changes the way memory players can decide and allocate business, making their environment much more secure and protected on the downside," Barclays analyst Tom O'Malley wrote in a May note.

See more: Micron and Sandisk shares could soar further thanks to a software-like subscription model

-Christine Ji

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06-16-26 0806ET