With 50 such stocks quoted on the exchange with a total market capitalisation of $7.8 billion, overall the sector yielded a 16.8% return to investors. However, Michael Liebreich, chief executive of New Energy Finance, warns that individual stocks may significantly under perform and there is no obvious pattern among the top-performing equities. Nonetheless, “Going into 2007, [it is] clear that clean energy has moved into the mainstream of the energy industry and has a major role to play in combating climate change,” said Liebreich.