Interesting question. But aren't there many assets that are bounded? Theoretically, a simple treasury bond is bound by 0, since market participants would just hold physical cash instead of accepting negative rates. Obviously, we are in the midst of a lot of central bank experimenting with NIRP and it is now readily apparent that empirically, rates can breach the zero lower bound, although I doubt by too much. I would say that a lower bound still exists, just somewhat lower than thought. Moreover, aren't T-bills considered assets? They may have short lives, but they are still considered to be assets. Investors just roll them to produce a virtually continuous investment in the T-bill asset class. So couldn't the same argument be applied to a long or short vol portfolio?
So there is a breakdown here in terminology. Assets that have value beyond 12 months are referred to as capital assets. Assets that terminate in value in under 12 months are referred to as money market instruments. So Bonds are typically referred to as capital assets and t-bill are money market instruments.
Bonds have no where near zero rates, those are only money market instruments. Also bonds produce both a cash and a capital component to them. I like to think of an asset as something that one can sit down value the asset from a known set of cash flows. Which is why I don't like to think of Gold as an asset for example. But a variance swap, what is the known cash flow? There really is no way to value that asset long term. It has to be actively traded. We can value securities, bonds, annuities, mortgages all from their future cash flows. That is the standard CAPM model. But how would you value long term the future cash flows of a variance swap?
Good to see you again OC.