The New Energy Fund, a hedge fund of global sustainable-energy stocks, climbed 1.87 percent Tuesday, said CEO Mark Townsend Cox.

The growth was mainly due to Clean Diesel Technologies, a London AIM-traded company that said it would make its Nasdaq debut Wednesday under the CDTI ticker symbol.

The company, which makes catalysts, purification systems and other technologies that reduce pollution from diesel engines, saw AIM share prices rise 12.7 percent to 77.5 British pence on the news.

Cox said the New Energy Fund is up 2.2 percent for the month, which is a "real mark of recovery" after the Federal Reserve cut interest rates.

"Renewable energy is waiting for any excuse to move," he said.

The WilderHill New Energy Global Index is up 43.4 percent from the beginning of the year, reaching 415.77 points at the end of trading Tuesday. The index dipped from a previous high for the year of 406.61 on July 13 to 335.02 on Aug. 16, then climbed back up.