Most people think of stocks when financial markets are mentioned. That is where the action is and where the big money is made. That may be so, but investors should not ignore the promise of the bond market.
In my graduate school days, a required subject was Modern Portfolio Theory. Its author, Harry Markowitz, who, back in the 1950s, proposed that the optimal portfolio for most risk-adjusted investors was 60 percent U.S. stocks and 40 percent U.S. Treasury bonds. The idea was that these two asset classes were negatively correlated, meaning that if stocks went down, bond prices would increase and vice versa. Over time, this diversification would produce better returns than putting all your eggs in one basket.
For most of my career, this investment theory worked well. However, over the past decade, interest rates were at or near zero. This made the bonds side of this equation a drag on overall performance. As a result, more and more fund managers reduced their bond weighting as stocks continued to rise. And then came COVID.
During the initial COVID market crash, both bonds and stocks fell together. In the subsequent market rally, both asset classes went up simultaneously. They lost again when the Federal Reserve Bank started hiking interest rates. In 2022, the 60/40 portfolio suffered a 17.5 percent decline. That was its worst performance since 1937 and its fourth worst in 200 years.
Both prices of bonds and stocks rose together once again as inflation peaked. Investors started positioning for a time when interest rates would come down. In this period the Fed stopped tightening and inflation was beginning to weaken. In the meantime, stocks were increasingly being priced as if they were bonds.
The formula was the same for both asset classes. The present value of a stock (or a bond) was calculated as the worth of its future cash flows (earnings and dividends, or in the case of bonds, interest payments), discounted at prevailing interest rates. Therefore, when those interest rates go down, the value of the stock rises just like a bond. The reverse happens when rates rise.
It appears that inflation and the global central bank response to combat it (coordinated interest rate hikes) had forced the correlation between stocks and bonds to become much closer. This we know to be true. In a study they completed this year, Morgan Stanley, the brokerage firm, found that whenever U.S. inflation exceeded 2.4 percent over the last 150 years, there was an increase in the correlation between stocks and bonds. It also led to heightened volatility in both asset classes.
Morgan Stanley (and others) believe the past few years were an anomaly. It was a period where inflation spiked, driving the correlation between bonds and stocks together.
If we fast-forward to today, the picture has changed. Thanks to the Fed’s tightening program over the past two years, interest rates are now high enough to provide a healthy return to a bondholder. In addition, the market expects the Fed to begin cutting interest rates as early as September. If and when they do, and rates start to fall, bonds will rise in price giving holders significant capital gains in addition to interest payments.
Stocks, on the other hand, are already close to record highs and extended. In the best of all worlds, If the Fed cuts rates, equities should continue to gain, but likely at a slower rate than the price appreciation of bonds.
If this were to happen, one would expect the 60/40 portfolio should come back into vogue. Vanguard, one of the world’s leading fund managers, expects U.S. bonds to yield between 4.8 and 5.8 percent over the next 10 years, compared to 4.2 to 6.2 percent for stocks.
If they are right, taken together, a 60/40 portfolio may just be the optimal approach for a moderate-risk investor.