1 Bitcoin = $1,000,000 USD
21 Million Bitcoins = $21,000,000,000,000 ($21 Trillion USD)
21 Million Bitcoins = $21,000,000,000,000 ($21 Trillion USD)
if this happens we will all be rich
Doesn't matter really - gold is also (usually) not sold in tons but in ounces, same way will be sold BTC at later time in mBTC and Satoshis.
Gold is as of this moment almost 8 Trillion market cap, imho Bitcoin is superior to Gold so with that in mind I see the market cap at least at the same level or higher.
Btw. 8 Trillion market cap means 1 BTC is worth ~ 381 000 USD