Avoiding behavioural pitfalls When it comes to investing, the most common behavioural pitfalls can be categorized in two ways: cognitive errors, according to financial-research firm Dalbar. Its new study released Friday found the average investor in U.S. stock mutual funds earned 7.3% last year, sharply lagging the S&P 500’s 12% total return. The good news is that spread. But looking at Dalbar’s Quantitative Analysis of Investor Behaviour (QAIB) study, it…