Market Cap is nothing more than amount of circulating supply multiplied by the value of one single coin. Volume describes the amount of USD that have been traded in the last 24h, and Circulating Supply is the amount of accessible coins at the time in question.
A couple of days ago I've read an interesting comment about Market Cap and why it doesn't matter so I saved it. I'll just leave it here for you to read and you make of that whatever you will. :-)
"Inserting here post from meegwell from an other forum:
As a former student of finance at undergrad and grad levels, this whole argument drives me NUTS! This may have been posted here before (I apologize if so) but it is one of the best explanations as to why comparing coin market caps to real company equity market caps is so ridiculous. Even more ridiculous is to compare a coin cap to a country's GDP or some fraction of another currency (like US notes in circulation v. US denominated assets).
I know not everyone can always read WSJ articles so I am summarizing my own interpretation in my own words below (quoted when necessary).
https://www.wsj.com/articles/stop-talking-about-bitcoins-market-cap-1513015626
First, the underlying conclusion here is that a coins value is a lot more like the ASSET value of a global financial institution...not the value of it's owners equity position. If you were to look at the books of Ripple, Inc...I am quite sure the company's XRP holdings would be in the ASSET section of the balance sheet.
This is actually something I have been considering writing. It is sooooo spot-on when it comes to the market cap debate. Funny thing is, the article is attacking BTC folks that brag about market cap...it covers all the basis - apples and oranges to compare to a real profit-producing company's market cap.
BTC (or any coin itself) is not a profit producing company. So what if BTC market cap is bigger than Citigroup's - a better comparison would be to compare to Citigroup's ASSETS...which is $1.8 trillion. For VISA, don't compare market cap, compare daily transactions (337k vs. 468 million) at a minimum.
Then comparing a coin market cap to national GDP figures (often done when folks argue a price cant go there) is "like comparing two random numbers".
When comparing bitcoin market cap to any established global financial institutions correctly, BTC is still a "small fry".
So, onward and upward XRP Market Cap!!!! The comparison to currency is also flawed because it often only considers physical notes in circulation - probably should consider total US denominated assets....$220 Trillion.
Some other TOTAL ASSET valuations of well known financial institutions:
JP Chase: 2.56Trillion BofA: 2.28 Trillion Wells Fargo $1.9 Trillion
Food for thought....
meegwell"