Though we’re entering the heart of earnings season, don’t overlook how valuable the filing of Form 13Fs can be for investors. These quarterly filings allow investors to track which stocks Wall Street’s smartest and most successful money managers have been buying and selling.
Few, if any, billionaire investors have proven more successful over multiple decades than Duquesne Family Office’s Stanley Druckenmiller. Known for his relatively active trading style and his love for innovative tech stocks, Druckenmiller dumped shares of Google parent Alphabet (GOOGL 2.05%)(GOOG 2.06%) in the first quarter, and piled into the hottest member of the S&P 500 (^GSPC 1.01%): memory titan Sandisk (SNDK 3.99%).
Duquesne Family Office’s Stanley Druckenmiller is one of Wall Street’s most-followed money managers. Image source: Getty Images.
Duquesne’s billionaire boss rang the register on Alphabet
According to Duquesne Family Office’s mid-May-filed 13F, billionaire Stanley Druckenmiller sent all 385,000 shares of Alphabet (the Class A shares, GOOGL) to the chopping block.
Profit-taking is certainly a logical explanation for Duquesne’s boss to ring the register. Alphabet stock practically doubled over the two quarters (the third and fourth quarters of 2025) during which Druckenmiller was a buyer. Alphabet’s integration of artificial intelligence (AI) solutions into Google Cloud has helped reaccelerate sales growth for this high-margin platform and sent its stock catapulting higher.
“Google Cloud revenues grew 63% with backlog nearly doubling quarter on quarter to over $460 billion.”
Analysts Projection: +52% YoY
Google Results:
– Cloud Revenue: +63% YoY
– Cloud Backlog: +300% YoY$GOOGL $GOOG pic.twitter.com/zNkiP1vcd1— Qualtrim (@qualtrim) April 29, 2026
But this may not be the complete story.
Druckenmiller has also gone on record as stating that “AI may be a little overhyped now, but underhyped long term.” He likely recognizes that every hyped technological innovation over the last three decades has succumbed to a bubble-bursting event early in its expansion. Though Alphabet is well-diversified, with a virtual monopoly in internet search, it wouldn’t be immune if the AI bubble bursts.
Alphabet also isn’t the screaming bargain it once was. Its forward price-to-earnings (P/E) ratio of 24 represents a 15% premium to its average forward P/E over the trailing five years.
Image source: Getty Images.
Stanley Druckenmiller found a new AI apple of his eye
While Alphabet was given the boot, Duquesne’s billionaire chief purchased 38,500 shares of memory storage solutions provider Sandisk. Over the trailing year (as of July 16), Sandisk shares have rallied more than 3,200%, making it Wall Street’s top-performing S&P 500 component by more than 2,500 percentage points!
Druckenmiller’s optimism likely stems from Sandisk’s critical role in AI data centers. The company’s NAND flash memory, solid-state drives, and high-bandwidth flash are designed to support high data transfer rates in AI-accelerated data centers.
2027 EPS estimates for SanDisk $SNDK are about to bend backwards in time while still moving parabolically higher: pic.twitter.com/qRsPDqR5KA
— Consensus Media (@ConsensusGurus) May 3, 2026
The “issue” is that enterprise demand for these solutions far exceeds their supply. This chokepoint is stymying an even faster data center build-out, but also affording Sandisk a level of pricing power and gross margin it’s never seen before.
In September 2025, Wall Street was forecasting less than $10 in full-year earnings per share (EPS) for Sandisk in 2027. Today, this EPS forecast is approaching $208. If memory supply shortages persist, Sandisk (and Stanley Druckenmiller) will be sitting pretty.
