Coherent risk measure

A coherent risk measure is a way of measuring the risk that an investment carries. It seeks to measure all of the potential losses from the investment in such a way that is easy to understand and compare, and takes into account the chance of a bad outcome happening. It also aims to be consistent, so that the same measure is used no matter what investment is being considered. It's like a score that tells you how risky an investment might be, so that you can decide if it is worth taking the risk.