What is Upside risk?

In investing, upside risk is the uncertain possibility of gain. It is measured by upside beta. An alternative measure of upside risk is the upper semi-deviation. Upside risk is calculated using data only from days when the benchmark has gone up. Upside risk focuses on uncertain positive returns rather than negative returns. For this reason, upside risk, while a measure of unpredictability of the extent of gains, is not a “risk” in the sense of a possibility of adverse outcomes.