Vector Commodity Management LLPâ??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. Vectorâ??s trading of mainly crude and oil products resulted in a 4.9 per cent loss from January through April, the letter showed.