Tesla shares up more than 6 percent Thursday after delivering a better than expected earnings report. On the investors call Wednesday, Tesla CEO Elon Musk said the company is getting 1,800 daily reservations for the Model 3, and predicts sales of the Model S to increase in the second half of the year. Annie Palmer, Technology Reporter at The Street, says investors are cheering this news, but are wary of the mounting costs for the company.