You can check out above graph to see how the market cap of ZCash has changed over time. The market cap value depends on the value of ZCash on that particular day and number of ZCash in supply at that day.

How is ZCash Market Cap calculated?

The ZCash Market cap is calculated using a simple formula. You can find it below:

ZCash Market Capitalization in USD = Number of ZEC in supply X Price of one ZCash in USD

Since the price of ZCash is highly volatile you can see the market cap going up and down a lot. Sometimes price and market cap are not linear to each other due to increase in the supply of coins in the market and stable or decrease in the price of the coin. So you can say that it's not simple to predict the market cap of ZCash or predict the price of ZCash.