THE PLAN: Electric car maker Tesla Motors Inc. begins selling stock to the public on Tuesday. The company hopes to raise up to $211.2 million by selling 13.3 million shares priced between $14 and $16, plus an investment from Toyota Motor Corp.

THE RISKS: Tesla has never made a profit and sells just one car, the $100,000-plus Roadster. The company doesn't expect the red ink to go away until it releases the Model S, an electric sedan due in 2012.

THE PROMISE: Many analysts believe that the internal-combustion engine will soon make way for greener forms of powering cars, like electricity, as gas prices climb and environmental worries mount.