Palo Alto, California - Tesla is on course to overtake Toyota and become the world’s most valuable car company.
Shares in the electric car firm have rallied more than 170 percent since mid-March, reaching record highs of $1027.48 (R17 460) each on Wednesday.
It has put the US company within touching distance of overtaking its Japanese rival.
Tesla was worth about R3.1 trillion on Wednesday, compared to Toyota’s £170bn (R3.65bn) market capitalisation.
It is already worth more than three times the combined value of Ford and General Motors, valued at R419bn and R655bn respectively.
The surge has inflated Musk’s personal fortune, with the 48-year-old currently worth a £36.5bn (R785bn), compared to £16.2bn (R348.3bn) a year ago.
Tesla could be set for a further boost, with news that it plans to introduce a new low-cost, long-life battery in its Model 3 sedan in China later this year or early next. It expects the new battery will bring the cost of electric vehicles in line with combustion-engined models, and allow EV batteries to have second and third lives in the electric power grid.
For months, Tesla Chief Executive Elon Musk has been teasing investors, and rivals, with promises to reveal significant advances in battery technology during a "Battery Day" in late May.
New, low-cost batteries designed to last for a million miles of use and enable electric Teslas to sell profitably for the same price or less than a petrol vehicle are just part of Musk's agenda, people familiar with the plans told Reuters.