Bond yields and equities - it takes two to tango

In recent months inflation expectations have been on the rise both in India and the developed markets and its impact has been felt on bond yields globally, central bank QE (quantitative easing) notwithstanding. Since then a new narrative has been taking hold amongst some market bulls. This new narrative is that the long-term correlation between bond yields and equities is positive, and hence is not a cause for alarm among equity investors. If expectations of better growth is driving inflation upwards and results in a rise in yields, then it reflects optimism on the economy and equities are likely to do well in such a scenario, is their argument. Is there data to support these claims? Is increase in bond yield actually good or bad for equities?

Inconsistent narratives

When movement of bond yields in any direction is used as a justification for equities to go up, then you must become circumspect. Since the launch of monetary stimulus last year globally by central banks and the crash in bond yields and deposit rates, the narrative that was used to justify a bull case for equities (which played out since the lows of March 2020) was that there is no alternative to equities. Hence, when bond yields actually start moving up as they have since early part of this year, an alternative for equities is actually emerging. So, market bulls have now shifted the narrative to why increase in bond yields this time is positive for equities as in their view bond yields are rising in anticipation of better economic growth. Well actually by this logic, last year bond yields fell in anticipation of a recession, so ideally it should have been negative for equities, right? Logic is the casualty when goal posts are changed.

Economic theory vs reality

Theoretically, increase in bond yields is negative for equities. This is for four reasons.

One, increase in yields will make borrowing costs more expensive and will negatively impact the profits of corporates and the savings of individuals who have taken debt.

Two, increase in bond yields is on expectations of inflation and inflation erodes the value of savings. Lower value of savings, implies lower purchasing power, which will affect demand for companies.

Three, increase in bond yields makes them relatively more attractive as an investment option; and four, higher yields reduce the value of the net present value of future expected earnings of companies. The NPV is used to discount estimates of future corporate profits to determine the fundamental value of a stock. The discounting rate increases when bond yields increase, and this lowers the NPV and the fundamental value of the stock.

What does reality and data indicate to us? Well, it depends on the period to which you restrict or expand the analysis (see table). For example if you restrict the analysis to the time when India had its best bull market and rising bond yields (2004-07), the correlation between the 10-year G-Sec yield and Nifty 50 (based on quarterly data from Bloomberg) was 0.78. However if you extend your horizon and compare for the 20 year period from beginning of 2001 till now, the correlation is negative 0.15. The correlation for the last 10 years is also negative 0.75.

In the table, we have taken 4 year periods since 2000 and analysed the correlation, on the assumption that investors have a 3-5 year horizon. The correlation is not strong across any time period except 2004-07 . It appears unlikely we will see the kind of economic boom of that period right now. That was one of the best periods in global economy since World War 2, driven by Chinese spending and US housing boom as compared to current growth driven by monetary and fiscal stimulus, the sustainability of which is in doubt in the absence of stimuli. This apart, Nifty 50 was trading at the lower end of its historical valuation range then versus at around its highest levels ever now. Inflationary pressures too are higher now. In this backdrop, the case for a strong positive correlation between equities and bond yields is weak.

What it means to you

What this implies is that the data is not conclusive and claims that bond yields and equities are positively correlated cannot be used as basis for investment decisions. At best, one can analyse sectors and stocks and invest in those that may have a clear path to better profitability when interest rates increase for specific reasons. For example, a company having a stronger balance sheet can gain market share versus debt-laden competitors; market leaders with good pricing power can gain even when inflation is on the rise.

A final point to ponder upon is whether a market rally that has been built on the premise that there is no alternative to equities in ultra-low interest rate environment, can make a transition without tantrums to a new paradigm of higher interest rates even if that is driven by optimism around growth. An increase in Fed expectations for the first interest rate increase a full two years from now, caused temporary sell-offs across equites, bonds and emerging market currencies, till comments from Fed Governor calmed the markets. These may be indications of how fragile markets are to US interest rates and yields.