I wrote a review of the Big Short. Since then I have spoken and emailed with many of the principal characters that were cartooned. They don’t like the movie because it pushes blame in the wrong directions. That it is a distraction while the other hand did the sleight of hand.
They are right. But it is still a good movie.
Any large scale financial rise and fall has many dynamics and none is more powerful than greed and the propulsion of momentum.
For a marketplace to work efficiently it must have transparency, a fair unbiased evaluation of quality and price from which a buyer or seller may give an informed price premium or a discount. All the sides must have some fiduciary obligation that binds them to an ethical standard. If they are riskless they are possibly guilty of something for which no laws, legislation or compliance yet exists.
A marketplace must have some mechanism that works as a bid and offer: “We are buying this at this price””we are selling this at this price” and there’s a difference between the bid and the offer and that is called the spread. Like a currency exchange, rates are established by something more reliable than just market tolerance.
Marketplaces also must possess some mechanisms to hedge. Oil for example….
Airlines lock in costs for oil years in advance, they take delivery of the actual commodity on demand. They are buying something that has not yet been produced.
The other side of that transaction is that someone (or something) has guaranteed that price way into the future. They may, or may not, take, or lose, money. They may in turn also have hedged their risk of downside by buying oil futures from another seller. And so on.
That marketplace works extremely well. If a speculator buys contracts for oil futures they do not have to put the barrels in their living room. The oil contracts can deliver oil barrels or it can be the profit.
I am bullish on the Venture Capital market.
History is a record of surprises. The sun rising yesterday is not history, it was expected and although might have been lovely there will be a lifetime more. I think if the market does peel back several layers it will come as a surprise.
Lets say I am investor in a venture capital fund that has several unicorns (which I do times x). That Venture Capital fund is my mutual fund for alternative assets. I want to hedge my position. There is no mechanism that allows me to essentially short a non public portfolio company. I am an investor in Venture Capital fund XYZ, I am happy with that investment but I feel one unicorn company in that fund is headed for big correction down. I want to not only remove that from my ‘mutual fund’ but I also want to short it. I want to hedge my bet and also profit from the collapse of the unicorn. 
For example in a somewhat different scenario. I think the stock  market will go down. I can short the S&P index. Now let’s say that one company in the index, say IBM, will go up in value while the rest of the index goes down. I can buy calls in IBM.
There can’t be a ‘big short’ in unicorns. And that’s not good. Simple two sided marketplaces don’t work when the dollars are so big. Uber at a valuation close to $100b hasmore room to go down then to go up. Now what?