Bill Gates’ Biggest Investment Regret: A Lesson for Every Investor

Bill Gates’ $150 Million Apple ‘Oops’

In 1997, Microsoft made a $150 million investment in Apple, a struggling company at the time. By 2003, they sold their stake for $550 million, a decent profit. But that same stake would be worth a staggering $184 billion today. In a 2025 interview, Bill Gates called selling their Apple shares “foolish, foolish.”

Gates explained that Microsoft had quadrupled their money, Steve Jobs seemed uncertain, and antitrust lawsuits were looming. Locking in the profit felt like the right move at the time. Looking back, it’s a classic example of the disposition effect—the tendency to sell winners too early and hold onto losers too long.

Warren Buffett’s Invisible Losses

Warren Buffett, the legendary investor, has a different take on his biggest mistakes. He told students at the University of Nebraska that he doesn’t lose sleep over stocks that didn’t pan out. His real regret is the massive profits he missed by hesitating on obvious opportunities.

Buffett famously passed on investing in Google in 2004 and Netflix in 2007. These missed opportunities cost him billions, but the pain wasn’t reflected in Berkshire Hathaway’s financial statements. The lesson? Opportunity cost can be just as damaging as making a bad investment.

Why We Fall for the Trap

Why do we, as investors, fall into this trap? There are several psychological factors at play:

• Loss aversion: We feel the pain of a loss more acutely than the pleasure of an equivalent gain.
• Mental accounting: We like to “lock in” profits to feel a sense of accomplishment, even if it means missing out on even greater gains.
• Attention bias: We tend to focus on the immediate gains and losses, overlooking the long-term potential of our investments.

Breaking the Cycle

So how can we avoid repeating the mistakes of billionaires? Here are some tips:

• Pre-commit a hold period: Decide upfront how long you’ll hold an investment before you sell.
• Automate rebalancing rules: Set rules for selling when a position reaches a certain percentage of your portfolio, instead of reacting emotionally.
• Run an opportunity-cost audit: Regularly review the ideas you almost invested in and track their performance.
• Journal the thesis, not the price: Focus on the fundamentals of your investment, not just the daily price fluctuations.

The Power of Compounding

The key takeaway? Be patient. Had Microsoft held onto its Apple investment, it would now be worth nearly half of its entire cash pile. Compounding works wonders over time. Let your winners run, and you’ll be rewarded in the long run.

Think Like a Billionaire

Bill Gates and Warren Buffett may have different approaches to investing, but they both agree that discipline and patience are key. Remember, the deadliest investing mistake is often a psychological one. Don’t let fear or greed dictate your decisions.