Bitcoin (BTC) has been engaged in a predictable up and down pattern where it absolutely crashes at the beginning of any year and then sky-rockets as the year nears its end. Bitcoin held steady at around $19,000 in December 2017, and then sure enough – crashed big time to around $6,000 at the beginning of 2018. At the time of writing, March 8th 2018, the price of Bitcoin is relatively stable between $10,000 and $12,000. In my opinion, the price will run again soon.

•   Liquidity Risk — In certain circumstances, such as the disruption of the orderly markets for the bitcoin futures contracts in which the Fund invests, the Fund might not be able to acquire or dispose of certain holdings quickly or at prices that represent true market value in the judgment of ProShare Advisors. Markets may be disrupted by a number of events, including but not limited to cyber-attacks, economic crises, natural disasters, new legislation, or regulatory changes inside or outside the U.S.
Note that you could just keep bitcoin on CryptoFacilities waiting to make the trade so you don't have to wait to move the bitcoin you bought over. This is called see-saw arbitrage model, where you keep funds on both exchanges to avoid having to wait. This is fine, but you can't ignore that there is extra capital being used in the play, so it affects your rate of return and capital utilisation. We will not use this method, we will do a full, complete, legitimate arbitrage process.