Circle of Competence: The more certain you are about the business outcome, the less risky it is.
Time Horizon: Shorter the time-horizon, higher the risk. Benjamin Graham: "In the short term, markets are a voting machine but in the long-term, it is a weighing machine."
Quality of Business: The higher the likelihood that business can keep earning above average returns, the better the business.
Quality of Management: Is Management looking after minority interest.
[Standard Deviation and Beta are NOT good proxies of risks.]