At the core of modern finance theory is a simple but powerful idea: There’s a price tag for earning a higher return – higher risk. Defining risk is a slippery concept, although not for want of trying with an ever-lengthening list of quantitative metrics. But more choices don’t always lead to more clarity. If you ask ten different investors (or money managers) to explain investment risk, you could easily hear ten different answers. This is no trivial point since quantifying risk is essential for managing it, even if the best-laid plans for profiling risk have limits and don’t always unfold…