Ben didn't want to lose money. He had had a rough time during the depression.

Try to establish the value of a company.

People don't like to buy things that are going down.

Try not to let your emotions affect your judgement.

Be careful of leverage. It can go against you.

Be aware of the level of the stock market. Are yields low and PE ratios high?

Remember that a share of stock represents a part of a business and is not just a piece of paper.