Risk-free assets: Are they truly risk-free? A comparative study of South African rates and instruments

Abstract

Determining the price of a financial instrument is something that happens every day in the financial markets. Every price starts off with a spot price adjusted for interest until maturity of the particular instrument. The interest is usually described as risk-free interest. The price so determined is the most basic price that an investor is willing to pay if not risk is involved. Risk-free assets, then, are securities of which the future rates of return are known with certainty. An exceptional degree of confidence in the issuer of the security brings about this certainty. Risk-free assets are normally in the fixed income securities (capital markets) investment category or in the liquid money market instruments such as treasury bills, category. This study attempts to determine whether the risk-free rates used by treasury managers and traders in South Africa to formulate their bond yield curves and which are used in valuation models, may be deemed risk-free. The study specifies certain criteria that an asset must satisfy in order to be used as a risk-free asset. Short term and long term South African instruments are compared to the US counterpart instruments, to gain an understanding of the South African instruments relative to the US ones. The behaviour of the risk-free instruments used in South Africa is also compared to the FTSE/JSE All Share Index and gold spot prices, which are perceived to be a risky asset classes. To gain some understanding of the behaviour of these instruments, analyses were done from different angles. The standard deviations of the daily percentage changes of the R157 were significantly lower than that of the ALSI and the gold spot price change. Compared to the ALSI and gold spot price, therefore, the R157 may be deemed a “low risk” instrument. The JIBAR was even less volatile that the R157. Interestingly, the US instruments were substantially more risky than the SA instruments over the analysis period. Also the JIBAR may be labelled “low risk” in this context. To improve on the comparisons especially where the magnitudes of change and the bases were very different, indices were used to compare the different instruments. Based on the index change, the JIBAR was now more risky than the R157. The ALSI and the gold spot was sill substantially more volatile than the JIBAR and R157. On this basis, the US instruments appeared less volatile but still more volatile than the SA instruments. It may be noted that the volatility of the US instruments were greatly influenced by the recent financial crisis.