I really disagree with this advice. You should always pay attention to the yields when you buy any financial asset. Buying based on rules is silly. If stocks

I really disagree with this advice. You should always pay attention to the yields when you buy any financial asset. Buying based on rules is silly. If stocks are paying 1.5% yields, and corporate bonds paying 7.5%, as they were in 2000, don't buy stocks! If stocks are paying 5.2% and long term bonds 8% like they were in 1978, go long on stocks (stock dividends will increase as nominal national income increases, usually about 5% a year, if stock prices can be a better buy even if dividends are lower than bond yields). The market is not rational, not even close. But if you are investing long term, and behave rationally yourself (buying stocks when cheap, buying bonds when stocks are expensive) you can beat the market. Right now is a really tough time to invest because both stock yields and interest rates are abnormally low. I'd probably maintain a balanced portfolio, but keep the bonds short term in hopes of a rise in interest rates in a few years.