Q I recently popped into a newsagent to buy a chocolate bar, and was told there was an extra charge for using my debit card as it costs the shop money if a customer buys something for less than €5 ...

Wayne A. Thorp, CFA, is a former AAII vice president. He was head of research and analysis and a senior financial analyst at AAII. Thorp was the creator and lead analyst for AAII Sentiment Investing ...