The Globe and Mail reports in its Tuesday edition that a key question for investors to consider is: How volatile are my investments? The Globe's guest columnist Robert Gerlseck writes that one measure to assess this is beta. Put simply, beta measures how volatile a stock is compared with movements in the broader market. The market itself is assigned a beta of 1.0. A stock with a beta greater than 1.0 is more volatile than the market; below 1.0, less volatile. In theory, high-beta stocks outperform in bull markets and fall harder in downturns. Low-beta stocks rarely lead rallies but may provide downside protection. Betas cluster by sector, with technology companies often having higher betas due to their earnings and share prices being more sensitive to economic conditions. Nvidia's beta is 2.31. Meta sits at 1.28. Companies that sell essential goods and services post lower numbers. Think grocery retailers and utilities. Loblaw is 0.30. Hydro One is 0.22. Beta may seem like a magical stock-picking tool to spot which shares will surge on sunny market days and which ones will hold up in a storm. But it has limitations. Successful Investor editor Scott Clayton says beta should be one factor among many to evaluate a firm.