Diversification may preserve wealth, but concentration builds wealth.

Risk comes from not knowing what you're doing.

Never invest in a business you can't understand.

Don't invest in pieces of papers (stocks), invest in great businesses underlying them.

Never be afraid to ask for too much when selling or offer too little when buying.

Most people get interested in stocks when everyone else is. The time to get interested is when no one else is. You can't buy what is popular and do well.