One of my favourite tales of investment stupidity is the story of the Beardstown Ladies. This group of grannies from a tiny Illinois town became famous in the 1990s when their investment club reported annualized returns of more than 23% for a decade. These Buffetts in bonnets wrote five books about their stock-picking acumen, which sold hundreds of thousands of copies, and they toured the US, celebrated as folksy, common-sense geniuses. Then someone checked their numbers.
It turned out that when the ladies calculated their returns, they included new money they had added during the year. Their actual investment returns over the decade were 9.1% annually, compared with almost 15% for the S&P 500. If you happen to find a Beardstown Ladies guide in a used bookstore one day, grab it: they’re collectors’ items now.
As the year-end approaches, you’ll likely want to know how well your own portfolio has done during the last 12 months. If you didn’t add or withdraw any money during the year, calculating your return is easy. Let’s say your portfolio’s value was $50,000 last December 31, and at the end of this year it has grown to $60,000.