Tesla shares are on fire.
The stock soared to $900 for the first time on Tuesday; that's on the back of a 20 percent one-day surge Monday - its best one-day gain in 7 years.
The latest catalyst for the Tesla run up?
Investors are betting Tesla is way ahead of the competition when it comes to battery technology for electric vehicles.
Its partner Panasonic announced Monday that the battery venture it has with Tesla has turned profitable for the first time.
Panasonic says the demand for Tesla batteries is so brisk - it is expanding production to keep up - that's a sign Tesla may be turning the corner on the bottleneck that Elon Musk last year described as production hell.
Tesla shares have already doubled this year - and we're only a few weeks in. Tesla now is the world's second most valuable car company behind Toyota and has a bigger market value than General Motors and Ford combined even though it sells far fewer cars.
There are analysts out there who question that valuation since Tesla still doesn't generate the kind of cash its larger rivals do, which can be poured back into innovation.
But investors are betting big on Musk's vision of the future - which after some mis-steps is starting to show success...
It's delivering vehicles at its highest pace ever, planning to ramp up production this year and turned a profit for the second quarter in a row.
Tesla shares - up 17 percent on Tuesday.