When selecting an investment to add to a portfolio, what feature would reduce the overall...

Variance measures the dispersion of returns around the mean; lower variance indicates greater stability and less volatility. Adding a security with low variance and low correlation to the portfolio reduces overall risk .

High standard deviation = higher risk.

High beta = greater sensitivity to market moves .

Low alpha = underperformance, not risk reduction.

Thus, the feature that reduces portfolio risk is Low variance.