NEW YORK (AP) — Shares of Tesla Motors Inc. rose Friday on investor optimism that the electric car company's supply problems are being resolved and the ramp up in production of its key new model is on schedule.

THE SPARK: George Blankenship, Tesla's vice president for sales, said in a company sponsored blog post Thursday that Tesla is producing 10 of its new Model S sedans per week and has delivered 50 cars so far. He also outlined some of the supply problems that delayed the vehicle's release.

THE BIG PICTURE: Tesla, the brainchild of PayPal billionaire and SpaceX founder Elon Musk, now has two all-electric models on the market, the $109,000 Roadster and the new Model S, which starts at $49,900 after a federal tax credit. The Model S went on sale in June, and Tesla said it had more than 11,500 reservations for the sedan by June 30.

Tesla has lost money since sales of the Roadster began in 2008, and the company is banking on the cheaper Model S to expand its market. Tesla began selling stock to the public in June 2010 at an initial price of $17 per share.

THE ANALYSIS: Jefferies analyst Jesse Pichel backed his "Buy" rating for Tesla, predicting that Tesla will boost its production of the Model S to 15 to 20 cars per week in the first half of August and then double that figure to about 40 cars per week later in the month, before doubling it again in September.

Any further quality issue that emerges would certainly delay the ramp-up further, he said. "But we do not believe ramp delays are meaningful to the investment thesis on the stock," Pichel wrote in a note to investors.

THE SHARES: Up $1.12, or 4.3 percent, to $27.22 in afternoon trading, after peaking at $27.55 earlier in the day. Over the past 52 weeks, the company's shares have traded between $21.50 and $39.95.