Top 12 Quotes & Sayings by William O'Neil

So the first thing I learned about how to get superior performance is not to buy stocks that are near their lows, but to buy stocks that are coming out of broad bases and beginning to make new highs.

The market has a simple way of whittling all excessive pride and overblown egos down to size. After all, the whole idea is to be completely objective and recognize what the marketplace is telling you, rather than try to prove that the thing you said or did yesterday or six weeks ago was right. The fastest way to take a bath in the stock market or go broke is to try to prove that you are right and the market is wrong.

Forget the adage buy low and sell high.

My philosophy is that all stocks are bad. There are no good stocks unless they go up in price. If they go down instead, you have to cut your losses fast Letting losses run is the most serious mistake made by most investors.

90% of the people in the stock market, professionals and amateurs alike, simply haven't done enough homework.

Since the market tends to go in the opposite direction of what the majority of people think, I would say 95% of all these people you hear on TV shows are giving you their personal opinion. And personal opinions are almost always worthless … facts and markets are far more reliable.

I've never met a successful pessimist.

It is one of the great paradoxes of the stock market that what seems too high usually goes higher and what seems too low usually goes lower.

The whole secret to winning and losing in the stock market is to lose the least amount possible when you're not right.

If you own a portfolio of stocks, you must learn to sell the worst performers first and keep the best a little longer.

The majority of unskilled investors stubbornly hold onto their losses when the losses are small and reasonable. They could get out cheaply, but being emotionally involved and human, they keep waiting and hoping until their loss gets much bigger and costs them dearly.

Over-diversification is a hedge for ignorance.