Today is the birthday of the world's best investor: Warren Buffett. Here are his main lessons for investors:

1. Buy businesses, not stocks: View a stock as part of a real business, focusing on the quality of the company, not the price.

2. Patience is a virtue: The market rewards the patient; time is the friend of the quality investor.

3. Invest in yourself: The best investment is in your education and skills.

4. Know what you own: Invest only in businesses that you understand completely.

5. Value simplicity: Prefer simple and straightforward strategies, avoiding unnecessary complexity.

6. Avoid unnecessary debt: Excessive debt can ruin even the best investments.

7. Maintain a margin of safety: Buy stocks at prices that offer protection against valuation errors. 8. Focus on value, not price: Focus on the intrinsic value of assets, not the market price.

9. Surround yourself with people who are better than you: Being around people with competence and integrity improves your performance.

10. Be risk averse when others are greedy: Be cautious in euphoric markets and courageous in depressed markets.