Vector Commodity Management LLP�??s assets under management slumped 86 per cent this year after losing money since 2011.

The energy hedge fund run by former Goldman Sachs Group Inc. trader Gilbert Saiz managed $43m by the end of April, according to a letter to investors obtained by Bloomberg News. Its December statement showed assets of $318m. Vector�??s trading of mainly crude and oil products resulted in a 4.9 per cent loss from January through April, the letter showed.