Minimum volatility is part of a broader group of defensive strategies that have been in existence for decades. They are based on the low volatility anomaly, the phenomenon that lower-risk stocks outperform over time, contradicting the conventional wisdom that risk and reward go hand in hand.
Low volatility strategy indices attempt to exploit this anomaly systematically. The typical behavior patterns of low volatility strategies are that they go up less when the market is up and go down less when the market is down. They offer protection in down markets and participation in up markets.
You can now read the full whitepaper at the link below