Word emerged on Tuesday that President Obama may back a $7,500 tax credit at the point of sale for buyers of electric vehicles such the Chevy Volt made by General Motors (GM). Previously, Senator Debbie Stabenow (D-Mich.) had introduced legislation to this effect. The move is seen as more favorable for the industry than schemes that require the buyer wait until filing taxes before receiving the rebate. That news may be behind the pop in the Energy Strorage and Battery Technology Stocks Index, which is up 2.1% tod