Warren Buffetts Favorite ETF How $400 a Month Could Grow to $820,000

Why Warren Buffett Keeps Pointing to the S&P 500 📌

When Warren Buffett speaks, the market listens. Under his leadership, Berkshire Hathaway delivered a 19.7% annualized return from 1965 through 2025 — nearly double the S&P 500's 10.5% annual return over the same stretch. Yet Buffett has repeatedly told ordinary investors that they don't need to pick stocks like him.

"In my view, for most people, the best thing to do is to own the S&P 500 index fund."

That was Buffett's message at Berkshire's 2021 shareholder meeting, and it echoes advice he's given for decades. In fact, when he famously bet a hedge fund manager in the early 2000s that an S&P 500 index fund would beat a basket of hand-picked hedge funds over ten years, he chose the Vanguard S&P 500 ETF (VOO) — and won decisively. 🚨

For investors wondering where to park $400 a month, Buffett's answer has been remarkably consistent.

What Exactly Is Inside the Vanguard S&P 500 ETF? 🔍

The Vanguard S&P 500 ETF tracks the S&P 500 index, which holds 500 of the largest U.S. companies across all 11 market sectors. It's widely considered the best single barometer for American equities, covering roughly 80% of U.S. market value and over 50% of global equity market value.

Top 10 Holdings (Approximate Weights)

Buffett's case for the index fund rests on four pillars:

1. Simplicity — Picking individual stocks requires deep business analysis. "Never invest in a business you cannot understand," Buffett warns.
2. Beating the market is hard — Even professional money managers struggle to outperform the S&P 500 over long horizons.
3. America's engine — 75% of the world's 20 largest public companies are U.S.-based. "For 240 years it's been a terrible mistake to bet against America," Buffett wrote in 2016.
4. Ultra-low cost — VOO's expense ratio is just 0.03%, meaning investors pay $3 per year on every $10,000 invested. Most active managers charge far more for worse results.

Even among Buffett followers, the S&P 500-only approach sparks real disagreement. Here's how the two camps see it:

The Math Behind $400 a Month → $820,000 📈

Over the last three decades, the S&P 500 returned 1,790% (10.2% annually) — despite three recessions, 16 market corrections, and four bear markets. That track record underscores the resilience of U.S. equities and supports a patient, long-term approach.

Projected Portfolio Value (Assuming 10.2% Annual Return, Dividends Reinvested)

Technical context worth noting: The S&P 500 has historically found durable support near its 200-week moving average during major drawdowns, and long-term investors who kept buying through those dips captured the bulk of the subsequent recovery. Backtested data from prior cycles suggests that the bulk of the final portfolio value in a 30-year plan is generated in the last 7–10 years — meaning abandoning the strategy mid-way is the single biggest risk to the outcome.

📊 In-Depth Fundamental Analysis

The Bottom Line 🎯

Warren Buffett doesn't recommend the S&P 500 index fund because it's exciting — he recommends it because it works. The Vanguard S&P 500 ETF offers broad diversification, rock-bottom fees, and exposure to the world's most dominant companies, all in a single ticker.

For investors with a multi-decade horizon, $400 a month into VOO isn't a get-rich-quick scheme — it's a slow, boring, and historically effective path to meaningful wealth. Past performance does not guarantee future results, and equity markets can and will experience painful drawdowns along the way. But for those who can stay the course, Buffett's advice remains one of the most reliable playbooks available.

This is not financial advice. Consider your own goals, time horizon, and risk tolerance before investing.