.

Think about businesses, not the economy.

9. "Don't over-diversify."

Diversification beyond 15 stocks doesn't provide you with additional protection against systematic risk; don't do it.

As Warren Buffett says, diversification is an insurance against ignorance.

10. "Don't sell too early."

You don't need to sell just because the stock went up too much.

Selling a great company early is a big mistake.

Remember, the lowest it can go is always 0, but the upside is unlimited.

Keep it as long as the business does well.