The more confidence I have in each one of my stock picks, the fewer companies I need to own in my portfolio to feel comfortable.

Here is part of the tradeoff with diversification. You must be diversified enough to survive bad times or bad luck so that skill and good process can have the chance to pay off over the long term.

Figure out what something is worth and pay a lot less.

The secret to investing is to figure out the value of something - and then pay a lot less.

Choosing individual stocks without any idea of what you're looking for is like running through a dynamite factory with a burning match. You may live, but you're still an idiot.

If I plug my estimates into the Magic Formula, and it comes out cheap, that's good.

If you spend your energies looking for and analysing situations not closely followed by other informed investors, your chance of finding bargains greatly increases.