I want a Klein bottle.  There is a stock of 1000 waiwai on the wampum market.  It is not moving.  It is bidless.  But they travel well by air, so I take one waiwai from the stock, by buying it on the market.  The market moves against me.  I.e. the value of one waiwai increases.  I sent one waiwai to Alice by European swallow to pay for a Klein bottle.  Alice wants wampum, so she sells the waiwai on the wampum/waiwai market.  The market moves against her.  I.e. the value of one waiwai decreases.  Net impact on waiwai/wampum: Zen.

Youtube videos of my Klein bottle go viral.  1100 teenage girls in Uruguay want Klein bottles, at various times, 100 each day.  As more and more school girls trade wampum for waiwai, the stock of waiwai declines, the cost in wampum increases.  100 waiwai are held by pidgeons.  Alice takes the waiwai from the pidgeons and sells them for wampum the next day, but by that time 100 more Uruguayan school girls have pidgeons in the air.  For 11 days, the stock of waiwai on the wampum market is reduced by 10%.  Uruguayans 101 to 1100 pay 20% more for the waiwai, and Alice gets 118% as much wampum for her Klein bottles as she would have were the waiwai rates constant.  If Alice's ten cousins start marketing their Klein bottles to Moldovan gigolos, whose pidgeons are twice as slow, those transactions will remove twenty times as much waiwai from the supply/demand balance on the wampum markets, and the price will rise confoundedly.   The result will be a waiwai bubble.

PQ=MV, the value of the money stock is M, denominated in PQ/V.  Increasing V decreases M.  Increasing the number of times a waiwai can flip during a fortnight, say by using African swallows instead of pidgeons, will increase laden air speed, thus decreasing the wampum per waiwai.

Using bitpay keeps BTC in the air.  That creates a churning marginal demand which decreases the supply on the fiat market.  If you buy immediately before spending, and the merchant takes fiat, then the time in the air is small.  If you buy in anticipation, V decreases, and the effective air time, from the point of view of the exchange market, is quite long.  Using bitpay also adds to the bid and to the ask on the market, thus increasing liquidity, which in turn makes bitcoin marginally more efficient (less slippage) and less risky (as liquidity is available when it is needed).

If everyone makes a different color of Klein bottle, and everyone wants to collect the whole set, then there are N^2 pidgeon flights which need to occur.  The first pidgeon reduced the stock of waiwai by a factor of 0.999.  The second person, by a factor of 0.998,  the n^2 person by a factor of 1-0.001*n^2.  As a result the cost of a waiwai rises by a factor of k*e^(n^2).