sorry, I wasn't clear. I wasn't asking WHAT velocity of money is, I was asking someone to explain the author's velocity of money argument. i.e. transfering wealth out of btc accelerates the velocity.

q, m, v, and p remain relatively constant in that transaction unless the liquidity event causes a persistent decrease in the price level (no evidence that the current BTC market could support it, but also c.f. above my comments about immature markets and liquidity).