There is no doubt that our grievances against the British Empire had a sound basis. As the painstaking statistical work of the Cambridge historian Angus Maddison has shown, India's share of world income collapsed from 22.6% in 1700, almost equal to Europe's share of 23.3% at that time, to as low as 3.8% in 1952. Indeed, at the beginning of the 20th century, "the brightest jewel in the British Crown" was the poorest country in the world in terms of per capita income.
In expensive cities like San Francisco and New York City, net rental yields can fall as low as 2%. This is a sign that there is a lot of liquidity buying property for property appreciation, and not so much for income generation. This is a riskier proposition than buying property based on rental income. In inexpensive cities, such as those in the Midwest, net rental yields can easily be in the range of 8% – 12%, although appreciation may be slower.
An obvious example is over exposure to bank stocks, which have been excellent investments for over a century.  Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise.  Being less exposed to bank shares in the last few months could have preserved some capital.  So, a more diversified approach can help mitigate some of these risks.