… One of the keys to being successful at investing over the long term is to stick to businesses and industries within your circle of competence. Put another way, you should invest only in businesses that you know and understand.
… One mistake that people often make is to assume that the stock markets will decline when the economy is in recession or one is forecasted. Being a math geek I went back and looked at the correlation between US GDP and US stock market returns over the past 80 years. The results will probably surprise you.