Guy Spier's top holdings (June 2026) include Micron Technology Inc. (MU), a multinational corporation that specializes in computer memory and data storage technologies.

Guy Spier is the managing partner of Aquamarine Capital and the author of "The Education of a Value Investor." He manages the Aquamarine Fund, a Zurich-based investment partnership that follows a long-term value investment philosophy.

Micron Technology Inc. (MU)

Micron Technology Inc. designs and manufactures essential memory and storage products, including dynamic random-access memory and flash memory. Its hardware is utilized across various sectors, including data centers, mobile communications, and the automotive industry. Micron Technology Inc. has a market capitalization of $1.1T, with Guy Spier's position currently valued at $194.2M. Wall Street analysts have established a price target of $805.94 for the stock, while discounted cash flow models estimate a value of $385.9 per share.

Here's an overview of Guy Spier's trades in Micron Technology Inc.:

American Express Co. (AXP)

American Express Co. is a global provider of payment and travel-related services for consumers and businesses. The company is primarily known for its credit card issuing, merchant acquisition, and network services. The company's market cap stands at $215.94B, while the current value of Guy Spier's holding is $66.46M. Market analysts maintain a price target of $385.9, and the discounted cash flow analysis suggests a value of $391.72 per share.

Here's an overview of Guy Spier's trades in American Express Co.:

Berkshire Hathaway Inc. (BRK.B)

Berkshire Hathaway Inc. is a massive holding company with subsidiaries involved in insurance, freight rail transportation, and energy generation. The company also maintains a significant portfolio of equity investments in diverse sectors. This holding in Guy Spier's portfolio is currently worth $57.05M. According to discounted cash flow calculations, the company shows a value of $455.49 per share.

Here's an overview of Guy Spier's trades in Berkshire Hathaway Inc.: [STOCKCIRCLE_EMBED_PLACEHOLDER_BRK.B]

Bank Of America Corp. (BAC)

Bank of America Corp. provides a broad range of banking and nonbanking financial services throughout the United States and international markets. Its operations include retail banking, corporate and investment banking, and wealth management services. Bank of America Corp. currently maintains a market capitalization of $366.18B, and the current value of Guy Spier's position is $39.62M. Analysts have set a price target of $59.5 for the firm, and its discounted cash flow value is calculated at -3.3 per share.

Here's an overview of Guy Spier's trades in Bank Of America Corp.:

Mastercard Incorporated (MA)

Mastercard Incorporated operates a global payments processing network, connecting consumers, financial institutions, and merchants. The company facilitates electronic forms of payment through its various credit, debit, and prepaid card programs. The market capitalization for the company is $436.47B, with the position in Guy Spier's portfolio currently valued at $32.48M. A price target of $633.64 has been issued by analysts, alongside a discounted cash flow valuation of $619.79 per share.

Here's an overview of Guy Spier's trades in Mastercard Incorporated: