Arithmetic on today's supply, not a forecast. It assumes nothing about whether Zcash could attract that much money.
A coin's market capitalisation is its price multiplied by the number of coins in circulation. Zcash has 16,749,987 ZEC in circulation at $1,151.57 each, which is $19.29B. Holding that supply still and putting XRP's $85.78B in its place gives $5,120.91 per ZEC.
A 4.45x move is modest, and a coin this far down the table reaching the one above it is the ordinary shape of a cycle, not an outlier.
Supply is held still, and in practice it moves: coins are minted, burned and unlocked, and every one of those changes the price a given market capitalisation implies. The figure also says nothing about whether the money exists to buy ZEC at that level, which is the part that actually decides a price.
$5,120.91 per ZEC. That is XRP's current market capitalisation of $85.78B divided across the 16,749,987 ZEC in circulation.
4.45x. Zcash trades at $1,151.57 today and XRP's market cap is $85.78B against Zcash's $19.29B.
No. It is one division: XRP's market capitalisation spread over the supply of ZEC that exists today. It assumes nothing about whether Zcash could attract that much money, and it holds the supply still when in practice supply changes.
It sets it. Market cap is price times circulating supply, so the same $85.78B of market cap spread over more coins gives a lower price per coin. This uses the 16,749,987 ZEC in circulation now.