There are millionaires and there are millionaires. The kind that people take seriously are those whose wealth is either a) highly liquid or b) somewhat stable,

There are millionaires and there are millionaires. The kind that people take seriously are those whose wealth is either a) highly liquid or b) somewhat stable, or c) some mix of these. If you own a million dollars of T-bonds, you're a millionaire. It's boring and highly liquid. If you own a million-dollar apartment in Manhattan, then also a millionaire, with a modest lag to liquidate it. If you own a million dollars of penny stock -- still a millionaire, but you might not get a bank loan on it. And while the bondholder and the apartment owner can turn their assets into cash in a single transaction, the owner of the penny stock is not going to be able to do that. The pool of capital on the other side of the exchange is just too small and too inactive. This might change, but so far it looks as though most companies are less interested in currencies (they report to their shareholders in USD, Euros and so on, not BTC) and more interested in a replacement for EDI and settlement systems.