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

How is Ripple Market Cap calculated?

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

Ripple Market Capitalization in USD = Number of XRP in supply X Price of one Ripple in USD

Since the price of Ripple 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 Ripple or predict the price of Ripple.