I'm a bit new to the whole lingo of The Valley. Could you explain a little more verbosely what you meant by that sentence? What is beta capital and beta investments? What is considered high? What denotes a boom and what is an unwind? How bad is a killer unwind, what does that mean really? Again, sorry, trying to learn the fast lingo here.
Beta is a coefficient that attempts to measure an investment's likelihood to move 'with the market.' The total market has a Beta == 1 by definition, with beta ratings above 1 indicating higher volatility/sensitivity to market movements, and vice-versa. See Wikipedia for how the calculations are made.
In this context, I a 'high beta investment' is likely to move with the market, ie) is dependent on some aspect of market performance. 'Beta capital' I think refers to using sources of capital that are likely to become more or less available depending on the market. I've never heard of capital sources being given beta values though, so I think this may be a finance/VC colloquialism rather than an actual calculated value.
Disclaimer: I am not a VC and may be totally wrong.
jkimmel explained what beta is. The Tech industry as a whole has a high beta, and the smaller loss making component (i.e unicorns) an even higher beta. I am using the term beta loosely here as most of the unicorns are not public so they don’t really have a true beta, but they do have a pseudo-beta. They are being funded by private equity funds in what are effectively private IPOs.
The problem is that private equity funds are a high beta asset class. In times of risk aversion investors pull their money out of high risk asset classes and put them into lower risk asset classes like large public companies and bonds. Relatively small changes in investor preferences can get amplified up the investment chain resulting in large swings in demand at the far end.
A hypothetical example might be 10% of investors pull their money out of private equity funds, the funds find that most of their money is locked up in illiquid assets like loss making high growth tech companies (i.e. unicorns). In order to return the 10% of capital requested they have to cut new investments by 50%. The unicorns find that they are not able to raise the money they need to expand at the pace they have been and so go on a crash program to achieving profitability. They lay off developers, cut back on outside services, and stop buying small start-ups. VCs and angel investors seeing this cut back on investing stop putting money into new firms further decreasing demand. All of this is not good if you are running (or wanting to start) a business based on rapid growth that needs lots of capital.