These rules are a mixture of time tested principles, so generously taught to us by the investment legends we greatly admire and dutifully respect.
At 3S Capital, we subscribe to the infinite wisdom of Mr. Charles T. Munger…. "I believe in the discipline of mastering the best that other people have ever figured out. I don’t believe in just sitting down and trying to dream it all up yourself. Nobody’s that smart…"
Warren Buffet 
Seth Klarman 
John Templeton 1. Don’t lose money.
2. Don’t forget rule No 1.
3. Always incorporate a very strong margin of safety in your entry price.
4. Always focus on the downside, the upside takes care of itself.
5. Stay within a well defined circle of competence. You can always expand the circle, but never drift outside of it.
6. High returns on capital in the form of free cash flow.
7. Avoiding where others go wrong is an important step in achieving investment success. In fact, it almost assures it.
8. Be greedy when the world is fearful, be fearful when the world is greedy.
9. Only invest/work with people who have their own skin in the game. They must have integrity, intelligence and energy. Without the first one, the other 2 will kill you.
10. When you make an investment, it goes down 50% and you don't want to buy more, you are speculating.
11. Markets are simply the equilibrium of supply and demand of liquidity.
12. You are a better investor if you think like a businessman and a better businessman if you think like an investor.
Charles Munger 
Ben Graham 13. Over-Confidence is the enemy of the investor. Stay humble, egoless, skeptical and flexible.
14. Bull markets are born on pessimism, grow on skepticism, mature on optimism and die on euphoria.
15. A bird in the hand is better than 2 in the bush.
16. The market can stay irrational a lot longer than you can stay solvent.
17. You are neither right nor wrong because the crowd disagrees with you. You are right because your data and reasoning are right.
18. Compounding interest is the most powerful force on earth.
19. The unexpected happens far more than one expects.
20. Focus is about being able to say NO.