The rocketing stock price of electric sports car maker Tesla made it more valuable than Fiat Tuesday -- even though the Italian auto giant produces 200 times more cars than the American upstart.

After a more than 50 percent gain in the past week, Tesla's market value topped $10 billion, compared to the Turin giant's $8 billion, as investors reacted to the company turning a profit in the first quarter and analysts boosting their forecasts.

Helped by a target of $103 a share set by Morgan Stanley analysts, the price surged again in early trade Tuesday to $97.12 before pulling back to close 5.2 percent lower at $83.24 -- leaving its market capitalization at a still-substantial $9.6 billion.

"What Tesla has accomplished isn't luck, it's real," said Morgan Stanley, pointing to its honor as Motor Trend magazine's car of the year and praise from hyper-critical Consumer Reports.

"Many funds approach an investment opportunity by first asking: does the company do something better or cheaper than anybody else? Tesla is beginning to convince the market it may do both," said Morgan Stanley.

The shares were up 55 percent in one week and 150 percent since the beginning of the year, after struggling through 2012 on production delays and questions about whether it could turn a profit.

The surge in the past week came on the back of the company's first quarterly profit in 10 years.

On May 8 the California-based firm announced $11 million in net income for the first quarter as revenues rose 83 percent from the prior quarter to $562 million.

Tesla cited strong global demand for its $62,000-$87,000 Model S, saying it is receiving orders at a rate of more than 20,000 per year worldwide, adding that it seen "significant upside potential in Europe and Asia."

Analysts at Bank of America-Merrill Lynch were equally impressed with the company but more skeptical of the stock's potential after such a run-up.

"Current stock price implies potentially unrealistic volume," the analysts said, forecasting sales growth in 2014 to just 31,000 units.

"Tesla would need to sell 2-3 times our optimistic 2013 volume in 2014 to justify current market levels."