The ongoing market crash is “an exceptional buying opportunity”, according to veteran US investor Bill Miller. “There have been four great buying opportunities in my adult lifetime”, Miller said last week. The first was during the 1973-74 stock market crash; the second was in 1982, when stocks traded on less than eight times trailing earnings; the third was after Black Monday in 1987, when stocks suffered their biggest one-day fall in history; the fourth was during the 2008-09 global financial crisis. “And this is the fifth one”, said Miller. Miller is famous for beating the S&P 500 15 years in a row between 1991 and 2005, an unprecedented run that earned him legendary status in investment circles. So, is it time to bet the farm on stocks?

Maybe not – Miller's strategy of buying when there's blood in the streets pays off most of the time but it cost him dearly in 2008, when he doubled down on financial stocks like Bear Stearns, Fannie Mae and AIG. Miller's fund returned 119 per cent last year and some still see him as a great, if imperfect fund manager; sceptics see him as a risk-taking perma-bull who does well in the good times but awful in the bad times.

That’s the problem with piggybacking investing – even with the most successful fund managers, it’s hard to know if they’re skilled or just lucky.