Professor Lionel Martellini of the EDHEC-Risk Institute discusses low volatility strategies as a type of popular smart beta strategy. Martellini examines the rationale for investing in low volatility strategies, exploring the issue of conditionality versus anomaly. He compares low volatility, minimum volatility, and low beta strategies and assesses which is the best defensive equity investment strategy. After reviewing the state of the art for low volatility portfolio construction, Martellini concludes with a discussion of the uses and misuses of low volatility strategies.