Quoting Wikipedia, Market cap is given by the formula
MC = N × P where N is the number of shares outstanding, and P is the closing price per share.
In the specific case of a crypto currency, one could assume that
N is the amount of coins in circulation and
P its current value.
How can the image below happen, given that Zcash, being a fork of Bitcoin, cannot (unless I missed something very important) be destroyed, thus
N can only grow.