That said, it does not have to be this way. It would be an exaggeration to say the performance of the Bearbull Income Portfolio gives a lie to this part of portfolio theory. However, it is quite clear how - over many years - it has combined excess rewards with low risks.
That much remains true after a full assessment of 2016's performance. Since the start of 2000, the income portfolio's monthly returns have averaged 0.56 per cent. Simultaneously, these returns have a standard deviation from the average - the most usual measure of risk in portfolio theory - of 3.1 per cent. Contrast that with returns from the FTSE All-Share index over the same 17 years - its monthly returns average is just 0.17 per cent, yet that has come with a standard deviation of 4.1 per cent.