The US oil boom is delivering a surprise for traders -- and it's costly (OIL)

REUTERS/Donna Carson The world's biggest oil traders are counting hefty losses. The price discount of US light crude doubled in a month, surprising trading desks, which have recorded losses in the tens of millions of dollars. It highlights the challenges of trading in WTI futures, the benchmark for US crude, when US pipeline and storage infrastructure struggles to keep pace with surging shale output. LONDON/NEW YORK