Everyone who is inside of an expanding bubble can't imagine another world where the bubble collapses on them. It's unimaginable because they haven't lived through it.

A lot of the philosophies of the businesses are just 'we're interested in getting customers now and if we're losing money with each customer now that's okay because we have this huge hoard of venture capital that we can subsidise the operation with and once we have the required number of tens of millions of customers and we drive our competitors out of business, then we can start to raise prices and become a proper business.'

You have to look at the fundamental raison d'être of the business - what is it doing? What's the nature of the business and what are its prospects for success? What are its prospects to break even and then return the sustained profit?

The stock market has gone up and if you are stock picking, that's fine, you may do a bit better than the market. But if you want to play in another game where you can get rapid increases of value and so on and so forth, this apparently has become the new parlour game, to invest in these companies and many their cases, the private equity that has been piling in onto of the venture capital is creating the unicorn, in other words the company with the $1 billion valuation.

If you have money draining out of the public equity markets, that inevitably affects the private equity market. They cannot exist going in different directions because somehow that will rent the fabric of the universe. It's just not permitted that that happens. Obviously there can be anomalies for brief periods of time but it just can't happen forever.

How many of the unicorn companies are really prosaic businesses - like limousine services or renting rooms in your house? The original VC firms from the '70's made their money and established the reputation of their respective brands by leveraging big cleverness with small capital, not small cleverness with big capital, and that's what's going on with these unicorns. That has never worked and it won't work this time. It doesn't produce venture quality returns, and it never will.

We're in one of the biggest tech bubbles we've ever had.