Arithmetic on today's supply, not a forecast. It assumes nothing about whether Cardano could attract that much money.
A coin's market capitalisation is its price multiplied by the number of coins in circulation. Cardano has 36,853,954,918 ADA in circulation at $0.2077 each, which is $7.65B. Holding that supply still and putting Stellar's $6.3B in its place gives $0.17092324 per ADA.
Cardano is already worth more than Stellar. Moving to the smaller cap would take ADA down to $0.17092324, which is 0.823x of what it trades at now.
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 ADA at that level, which is the part that actually decides a price.
$0.17092324 per ADA. That is Stellar's current market capitalisation of $6.3B divided across the 36,853,954,918 ADA in circulation.
0.823x. Cardano trades at $0.2077 today and Stellar's market cap is $6.3B against Cardano's $7.65B.
No. It is one division: Stellar's market capitalisation spread over the supply of ADA that exists today. It assumes nothing about whether Cardano 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 $6.3B of market cap spread over more coins gives a lower price per coin. This uses the 36,853,954,918 ADA in circulation now.