Growing up, I admired nobody more than Warren Buffett, the greatest investor ever. His achievement is towering. The market is an implacable opponent but here was a man who beat it year after year, making $75bn out of nothing but wisdom and charm. There was moral purity in his modesty, his ethics and his quiet attachment to home in Omaha, Nebraska. What footballer, politician or thinker could compare? 

Now 87, Mr Buffett wields huge influence over US business and finance, usually positive. He pushed companies to expense stock options, warned of danger in derivatives and taught the public to invest long term in low-cost index funds.

But how ever much you admire the man, his influence has a dark side because the beating heart of Buffettism, celebrated in a thousand investment books, is to avoid competition and minimise capital investment in the real economy.