$500M sounds like a typo. That is absolutely unheard of for a stealth company. For reference, Oculus had a $75M round last December, and they had ignited an entire VR developer community. Uber had a record setting round earlier this year and raised $1.2 billion. But Uber is... well, Uber.
They already raised $50mil Series A in February, it doesn't seem that unrealistic. Remember, a typical film budget for these guys easily breaks into the hundreds of millions.
