I believe the comment refers to the fact that Tesla bought a lot of bitcoins. So for their current valuation to make sense, either they have to succeed in monopolizing the auto market, or their bitcoins have to go up a lot in value.
You're right. I somehow misinterpreted that part of the comment. Having said that, I doubt that Tesla's Bitcoin investment could be a foundation for its current valuation (as of today, > $660B). The $500K BTC price implies ~10x growth, so the value of that $1.5B investment would equal to ~$15B, which is still far less than the target number.
