Tesla shares rise as investors are confident about the company's cash flow.

(Reuters)- Tesla shares jumped more than 12 percent on Thursday after the company convinced investors it was capable of generating positive cash flow and becoming profitable, and CEO Elon Musk apologized for previous controversial remarks.

The shares added about $6,27 billion in market value, valuing the company at $57,35 billion, surpassing General Motors to make Tesla the most valuable automaker in the United States.

Musk, in a conference call on Wednesday, said the company would not need to raise more money and that capital expenditures would be slightly below $2,5 billion in 2018, less than most analysts had expected.

But it was his remorse for previous remarks made to analysts that stood out at the conference. Previously, Musk had insulted some analysts—disconnecting investors and shareholders and wiping $2 billion off the company's market value.

“I would like to apologize for being impolite on the previous call. Honestly, I don’t think there’s really any excuse for bad manners. I was kind of violating my own rule in that regard,” he said.

In the previous quarter, Musk considered questions posed by two analysts "boring" and "idiotic," and refused to answer them.

The company's shares rose 12,2 percent to $337,68.

Tesla ended the second quarter with $2,78 billion in cash after spending $610 million on capital expenditures.

Analysts at Barclays suggested that Tesla used $458 million in credit, which boosted its cash reserves at the end of the quarter.

On Wednesday, Musk reiterated his goal of producing 6 Model 3 sedans per week by the end of August. After Tesla produced 5 per week in July, following several delays in meeting that goal, analysts were concerned about the possibility of maintaining that production rate.

"After three quarters in which investors were left in the dark regarding estimates for Model 3 volumes and margins, the feeling in the second quarter is that there might finally be some light at the end of the tunnel," wrote analysts at Evercore.

Tesla posted a record loss of $718 million in the second quarter, but investors and analysts focused on the positives and, above all, on Musk's behavior during the conference call.

At least three brokerages increased their price valuations, and one improved the stock's rating.