professionals while opposing options, which he saw as dangerous instruments in the service of ill-advised speculation. …The idea that speculation exacerbates commodity and stock price volatility dates back at least from the second half of …, originally applied to commodities and subsequently extended to securities, was that speculation is mostly beneficial …

-sharing between speculators and hedgers, and the price stability of 20 commodity futures markets. We find that margin increases … certain markets. The regulator should set margins by taking the heterogeneity of commodity futures markets into account …

speculates by forecasting futures price changes. The selective hedges we consider use different forecasts that range from the …