If you think about it, 0.0000048% of total US m2 money would be 504,000 usd.. half a million
So can we say that 1 Btc = $500,000?
No, not really. The M2 money supply isn't a realistic basis for Bitcoin's value -- unless Bitcoin completely
replaced all cash and fiat money savings accounts -- cash, check/savings/money market deposits, mutual funds, etc. Even then, Bitcoin's market valuation is more complex than that. I suspect Bitcoin and fiat currencies will exist side by side for quite a while anyway.
It might hit $500,000 in the coming years based on its speculative investment properties alone, but I don't think it will have such a clear relationship to the fiat money supply.