So there are only BTC1.8k new BTC mined daily. Volume wise we got about:
BTC4k @ Bitfinex USD/BTC
BTC4k @ Btc-e USD/BTC
BTC3k @ Stamp USD/BTC
BTC3k @ Coinbase USD/BTC
BTC3k @ Kraken EUR/BTC
BTC1.8k daily Gemini auction
BTC1k @ LocalBTC USD/BTC

or about BTC20k/day volume from somewhat believable sources

+BTC21MM CNY/BTC

and that's with a stable price in last 3months. Where is the volume coming from?  can't be same people selling to themselves just to pay exchange fees