Yes it is possible.
1 usd means 18.5 billion market cap.
Do you think there are more or less demand for monetary privacy than 18.5 billion usd?
Bear in mind, also to reach 18.5 billion market cap doesn't equal 18.5 billion dollars invested in Verge. That can be achieved with much smaller amount of money since probably there are coins that are not even for sale at any price.
The higher it goes, the less coins there will be available for sale since the current holders are so filthy rich that they do not care to sell anymore.