It always shocks me when a big trader comes out and says they're shorting a stock. Mostly, because I'd prefer to keep it quiet (people generally hate short-sellers, whether that's illogical or not). A hedge fund manager and Greentech Media contributor is advocating shorting First Solar. I figure, he's looked carefully at the industry, he must know something. So I thought I'd check it out. John Hempton of Bronte Capital says First Solar became a great company by innovating efficiencies in the manufacturing of solar cells. But he thinks that these efficiencies are largely evaporating as the price of solar-cell silicon material drops and competition from the semiconductor industry closes in fast.