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Posts Tagged ‘bonds’

Visible and General Historical Stock Regularities

Tuesday, June 23rd, 2009

What can you learn from these graphs? Actually, almost everything that there is to learn about investments—and I will explain these facts in great detail soon.
• The history indicates that stocks offered higher average rates of return than bonds, which in turn offered higher average rates of return than “cash.” However, keep in mind that this was only on average. In any given year, the relationship might have been reversed. For example in 2002, stock investors lost 22% of their wealth, while cash investors gained about 1.7%.
• Although stocks did well (on average), you could have lost your shirt investing in them, especially if you had bet on just one individual stock. For example, if you had invested $1 into United Airlines in 1970, you would have had only 22 cents left in 2002—and nothing the following year.
• Cash was the safest investment—its distribution is tightly centered around its mean, so there were no years with negative returns. Bonds were riskier. Stocks were riskier, yet. (Sometimes, stocks are called “noisy,” because it is really difficult to predict what they will turn out to offer.)
• There was some sort of relationship between risk and reward: the riskiest investments tended to have higher mean rates of return. (However, the risk has to be looked at “in context.” Thus, please do not overread the simple relationship between the mean and the standard deviation here.)
• Large portfolios consisting of many stocks tended to have less risk than individual stocks. The S&P500 fund had a risk of 17%, much less than the risk of most individual stocks. (This is due to diversification.)
• A positive average rate of return usually, but not always, translates into a positive com- pound holding rate of return. United Airlines had a positive average rate of return, despite having lost all investors’ money.
(You already know why: A stock that doubles and then halves has rates of return of +100% and –50%. It would have earned you a 0% total compound rate of return. But the average rate of return would have been positive, [100% + (−50%)]/2 = +25%.)
• Stocks tend to move together. For example, if you look at 2001–2002, not only did the S&P500 go down, but the individual stocks also tended to go down. In 1998, on the other hand, most tended to go up (or at least not down much). The mid-1990s were good to all stocks. And so on. In contrast, money market returns had little to do with the stock market. Long-term bonds were in between.
On annual frequency, the correlation between cash and the stock market (the S&P500) was about zero; between long-term bond returns and stock market around 30%; and between our individual stocks and the stock market around 40% to 70%. The fact that investment rates of return tend to move together will be important.