Billionaire investor Warren Buffett, chairman of Berkshire Hathaway, has long attributed much of his investing success to the foundational principles outlined in The Intelligent Investor — the 1949 classic by Benjamin Graham that Buffett has called “by far the best book on investing ever written.” More than seven decades later, the book’s core concepts continue to underpin Buffett’s own strategy and remain strikingly relevant in modern financial markets—especially in a world increasingly shaped by volatility, speculative sentiment, and short-term thinking.

Whether through his legendary long-term holdings in companies like Coca-Cola, American Express, and Apple, or in his sharp critiques of market euphoria, Buffett’s application of these timeless principles has made Berkshire Hathaway one of the most successful investment vehicles in history. Here are six key lessons that lie at the heart of that success.

Mr. Market is there to serve you, not instruct you

Benjamin Graham introduced the concept of “Mr. Market” as a moody business partner who offers to buy or sell shares at erratic prices. The allegorical figure “Mr. Market” represents the collective emotions of market participants. Each day, Mr. Market offers prices that may swing wildly based on sentiment, fear, or euphoria—but Graham, and by extension Buffett, urges investors to treat these fluctuations as opportunities rather than signals.Buffett has frequently stressed that intelligent investors do not let market prices determine their actions. Instead, they should assess the intrinsic value of a business and act when the market price deviates meaningfully from that value. “The stock market is designed to transfer money from the active to the patient,” Buffett has said, highlighting how emotional detachment and valuation discipline can create long-term outperformance.

Insist on a margin of safety

Perhaps Graham’s most enduring concept is the “margin of safety”—the practice of buying securities at prices well below their intrinsic value. This cushion protects investors from unforeseen errors, misjudgments, or economic shocks.Buffett has consistently applied this principle by avoiding high-flying growth stocks without a clear earnings base and focusing instead on durable businesses with stable cash flows that can be bought at reasonable valuations. It’s a defensive posture that has allowed him to compound returns through multiple economic cycles, limiting downside while preserving upside potential.

Invest with the mindset of an owner

At the core of Buffett’s philosophy is the idea that buying a stock is equivalent to buying a piece of a business. That perspective shifts the focus from short-term price movements to long-term fundamentals like earnings power, return on capital, and competitive advantage.

This owner mindset is reflected in Buffett’s reluctance to sell high-performing holdings. “Our favourite holding period is forever,” he wrote in his 1989 letter to shareholders. His investment in Coca-Cola—acquired in 1988 and still held decades later—is a textbook example of this philosophy in action, generating billions in dividends and unrealized gains.

Avoid the perils of herd mentality

Markets are frequently driven by crowd behavior, and Graham cautioned that following the herd often leads to subpar outcomes. Buffett has echoed this sentiment throughout his career, often positioning himself against prevailing market trends.

He famously sidestepped the dot-com boom of the late 1990s, citing a lack of understandable business models and unsustainable valuations. While Berkshire underperformed briefly during the mania, it preserved capital—and ultimately benefited as the bubble burst. Buffett’s contrarian posture isn’t about being reflexively opposite; it’s about independent thought grounded in rational analysis.

Diligence is non-negotiable

Graham emphasized rigorous analysis, and Buffett has taken that advice to heart. He and his late partner Charlie Munger read hundreds of annual reports, regulatory filings, and industry analyses each year—seeking not just numbers, but patterns of behavior and indicators of long-term value.

Their approach has consistently focused on key variables such as return on equity, consistency of earnings, and the quality of management. In a world awash with algorithmic trading and speculative narratives, Buffett’s research-driven discipline serves as a reminder that understanding the businesses behind the stocks is essential to sustained success.

Let compound interest work its magic

Buffett’s true investment “secret” is time. By investing in strong businesses and allowing them to grow over decades, he has harnessed the exponential power of compound interest. He likens it to a snowball rolling downhill, growing larger the longer it rolls: “The important thing is finding wet snow and a really long hill.”

The numbers speak for themselves. A $100 investment growing at 9.8% simple interest over 30 years becomes $394. But at 9.8% compound interest, it becomes $1,652. The difference is not in the rate—but in the reinvestment and the time horizon. Buffett’s reluctance to sell winning positions further amplifies this compounding effect, while minimizing capital gains taxes and transaction costs.

As markets get more unpredictable and noisy, Buffett’s six core principles offer a clear and steady guide. In a time when speculation often takes center stage, sticking to these fundamentals can help investors stay focused, make better decisions, and build long-term wealth.

Also read | 7 reasons why Warren Buffett’s $325 billion cash pile is a warning for Wall Street

(Disclaimer: Recommendations, suggestions, views and opinions given by the experts are their own. These do not represent the views of the Economic Times)