Stocks' plunge exposes the risks of complex low-volatility bets

New York

WALL Street's plunge last week has brought scrutiny to complex niche products to trade on volatility that market experts believe were poorly structured and exacerbated swings in stocks.

Only days before markets began to go haywire, Barclays chief executive Jes Staley warned about the risky investments at the World Economic Forum in Davos.

Many investors were using exchange-trade…