[snip]
To add; market caps are meaningless. You just need to dump the price down of a leading exchange, which in current thin market can be achieved with a fair number of coins, and the market cap tanks with tens of billions in value, and that just because of a few million value dump.
But if it's an outlier, the market will recover quickly and it won't be an issue. The more liquid a market is and the higher the trading volume, the better an indicator market cap is. And we've reached the point now where Bitcoin market cap is a good indicator.
I can't quite agree with this conclusion. There can be a really liquid market with active and agile orderbooks but if only a small amount of coins gets traded, no matter how fast, a market cap will be mostly a meaningless metric. It seems that trading volume itself is not a good indicator of how good an indicator a market cap can be. In this way, if we don't know how many bitcoins are being traded out of their total amount mined to date, we can't say if its market cap is a good indicator.
By definition, if there's a "really liquid market" as you put it, that presupposes a deep market. If it's a shallow market where only a small amount of coins get traded, by definition it is not a liquid market. You can disagree with the conclusion all you want, but you're contradicting your own point in doing so. You cannot have both a liquid market and a shallow trading depth. Those things are mutually exclusive by definition since one is an attribute of the other.
Yes, I agree that they are mutually exclusive, but you are apparently drawing a conclusion based on wrong premises, so the conclusion itself is also necessarily false. How so? Because you seem to forget about another variable, which can make a small amount of coins look bigger than an actually bigger amount of them. Here I refer to the velocity of money. Hypothetically, you can trade a sole bitcoin out of 21 million and get any trading volume because volume is determined by how often a certain amount of coins changes hands. There are at least two variables in the equation, while you are looking at only one of them. In other words, you can get a really huge trading volume on a completely shallow market. Now imagine how relevant is trading volume taken in isolation.