When weather risk veterans Mark Tawney and Bill Windle left global reinsurer Swiss Re in early July, it sent ripples around the small but fast-growing weather derivatives market. And the fact that they left one of the largest weather trading houses to set up a hedge fund reflects the market’s buoyancy.

Weather trading volumes have really started to pick up since September 2004 – and particularly in the past couple of months. It is hedge funds that are helping to fill the trading gap left by