In case of some of the any currency - the volume that flows through it.
If Ethereum is a go-to place to do equity crowdfunding in the future, and we estimate the volume of such operations at $120B a year, then - assuming it takes a month from the moment someone buys ETH to invest in an ETO, to the moment a startup sells it for a fiat money, Ethereum's market cap will need to be at least $10B to fulfil that need, and that would be a cap bottom then.
On top of that, there will be other uses, and of course speculation/hype factor, which you can count in as well.
Now, with the advent of stable coins, it's possible that most of the ETOs won't be funded using Eth, but a dollar derivative (e.g. MakerDAO), or a token represented by a locked-up asset (e.g. Digix). Right now MakerDAO uses Eth as a backing, so it doesn't change the math, but if the Digix model proves successful, it affect this calculations.
Another line of reasoning for Eth is that you have transaction fees, and here again you can easily calculate the money velocity, and a potential volume flowing through the system.
Finally, when PoS arrives, Eth will yield de facto dividends - that's planned to happen within a year, although it has been postponed a few times already.
For other cryptocurrencies - MakerDAO, Digix, or Ocean have economies that can be calculated in a similar way. A plenty of other ones to.
Now, if you say that there is a low chance of such projects being successful - keep in mind that all these projects aim high. If there is 1% probability that BananaCoin will really help people grow bananas, it will deserve a $100M valuation, since it will be worth $10B in case of success.
Oh oh, in case of some projects, if not most, their book to equity rate is very high by Wall Street's standards. Golem may seem overpriced with their $200M valuation (that is - you believe they either have <1% of success, or their target market cap is <$10B), until you realise they have around $100M-$150M in assets after their ICO. That's a lot of money they can spend to deliver the value.
If Ethereum is a go-to place to do equity crowdfunding in the future, and we estimate the volume of such operations at $120B a year, then - assuming it takes a month from the moment someone buys ETH to invest in an ETO, to the moment a startup sells it for a fiat money, Ethereum's market cap will need to be at least $10B to fulfil that need, and that would be a cap bottom then.
On top of that, there will be other uses, and of course speculation/hype factor, which you can count in as well.
Now, with the advent of stable coins, it's possible that most of the ETOs won't be funded using Eth, but a dollar derivative (e.g. MakerDAO), or a token represented by a locked-up asset (e.g. Digix). Right now MakerDAO uses Eth as a backing, so it doesn't change the math, but if the Digix model proves successful, it affect this calculations.
Another line of reasoning for Eth is that you have transaction fees, and here again you can easily calculate the money velocity, and a potential volume flowing through the system.
Finally, when PoS arrives, Eth will yield de facto dividends - that's planned to happen within a year, although it has been postponed a few times already.
For other cryptocurrencies - MakerDAO, Digix, or Ocean have economies that can be calculated in a similar way. A plenty of other ones to.
Now, if you say that there is a low chance of such projects being successful - keep in mind that all these projects aim high. If there is 1% probability that BananaCoin will really help people grow bananas, it will deserve a $100M valuation, since it will be worth $10B in case of success.
Oh oh, in case of some projects, if not most, their book to equity rate is very high by Wall Street's standards. Golem may seem overpriced with their $200M valuation (that is - you believe they either have <1% of success, or their target market cap is <$10B), until you realise they have around $100M-$150M in assets after their ICO. That's a lot of money they can spend to deliver the value.