I have worked with the CME in the past on product development (specifically CDS futures) and from my experience, they would not have missed anything this simple.  In fact, while I am not a huge fan of the concept of Bitcoin futures, as currently implemented, I do not expect any errors in the operation of the CME or CBOE futures contract.  I am sure that regulators will be questioning them on the back of the OKEX, as they should, and I am also quite positive the exchanges here will pass with flying colors.
The Fund generally does not expect to invest directly in futures contracts, option contracts and swap agreements (“Bitcoin Instruments”). The Fund expects to gain exposure to these investments by investing a portion of its assets in the ProShares Cayman Bitcoin Futures/Equity Strategy Portfolio, a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands (the “Subsidiary”). The Subsidiary is advised by ProShare Advisors, the Fund’s investment advisor, and invests directly in Bitcoin Instruments. Unlike the Fund, the Subsidiary is not an investment company registered under the 1940 Act. The Fund’s investment in the Subsidiary is intended to provide the Fund with exposure to commodity markets related to bitcoin in accordance with applicable rules and regulations. The Fund will invest up to 25% of its total assets in the Subsidiary. Except as otherwise noted, references to the Fund’s investment strategies and risks include the investment strategies and risks of the Subsidiary.
A Fund may in its discretion exercise its option to redeem such Shares in cash, and the redeeming shareholder will be required to receive its redemption proceeds in cash. In addition, an investor may request a redemption in cash which a Fund may, in its sole discretion, permit. In either case, the investor will receive a cash payment equal to the NAV of its Shares based on the NAV of Shares of the relevant Fund next determined after the redemption request is received in proper form (minus a redemption Transaction Fee and additional charge for requested cash redemptions, to offset the Fund’s brokerage and other transaction costs associated with the disposition of Fund Securities).
Cboe Futures Exchange, LLC (CFE) launched trading in Cboe bitcoin futures at 5:00 p.m. Central Time on December 10 under the ticker symbol "XBT". XBT℠ futures are cash-settled contracts based on the Gemini's auction price for bitcoin, denominated in U.S. dollars. Gemini Trust Company, LLC (Gemini) is a digital asset exchange and custodian founded in 2014 that allows customers to buy, sell, and store digital assets such as bitcoin, and is subject to fiduciary obligations, capital reserve requirements, and banking compliance standards of the New York State Department of Financial Services.3
In general, the Code defines (1) “short-term capital gain dividends” as distributions of net short-term capital gains in excess of net long-term capital losses and (2) “interest-related dividends” as distributions from U.S. source interest income of types similar to those not subject to U.S. federal income tax if earned directly by an individual foreign shareholder, in each case to the extent such distributions are properly reported as such by a Fund in a written notice to shareholders.
The Bitcoin Network’s functionality relies on the Internet. A broadly accepted and widely adopted decentralized network is necessary for a fully-functional blockchain network, such as the Bitcoin Network. Features of the Bitcoin Network, such as decentralization, open source protocol, and reliance on peer-to-peer connectivity, are essential to preserve the stability of the network and decrease the risk of fraud or cyber-attacks. A significant disruption of Internet connectivity affecting large numbers of users or geographic areas could impede the functionality of the Bitcoin Network and adversely affect a Fund. In addition to technical disruptions such as cyber-attacks, the potential elimination of the net neutrality regulations in the U.S. may have a negative impact on miners, Bitcoin Markets and the Bitcoin ecosystem. Any technical disruptions or regulatory limitations that affect Internet access may have an adverse effect on the Bitcoin Network, the price of bitcoin and the Bitcoin Instruments in which the Funds invest.
The Fund pays transaction costs, such as commissions, when it buys and sells securities (including through the Subsidiary, as defined below) or “turns over” its portfolio. A higher portfolio turnover rate for the Fund or the Subsidiary may indicate higher transaction costs and may result in higher taxes when the Fund’s shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the example above, affect the Fund’s performance. The Fund has not yet commenced operations as of the date of this Prospectus. Thus, no portfolio turnover information is provided for this Fund.
Bitcoin is maintained on the decentralized, open source protocol of the peer-to-peer bitcoin computer network (the “Bitcoin Network”). No single entity owns or operates the Bitcoin Network. The infrastructure of the Bitcoin Network is collectively maintained by a decentralized user base. The Bitcoin Network is accessed through software, and software governs bitcoin’s creation, movement, and ownership. The value of bitcoin is determined in great part by the supply of (which is limited), and demand for, bitcoin in the global exchange markets for the trading of bitcoin (individually, “Bitcoin Exchanges” and collectively, the “Bitcoin Exchange Market”), market expectations for the adoption of bitcoin and the volume of private user-to-user transactions.
In general, for purposes of the 90% gross income requirement described in subparagraph (a) above, income derived from a partnership will be treated as Qualifying Income only to the extent such income is attributable to items of income of the partnership which would be Qualifying Income if realized directly by the RIC. However, 100% of the net income of a RIC derived from an interest in a “qualified publicly traded partnership” (a partnership (x) the interests in which are traded on an established securities market or readily tradable on a secondary market or the substantial equivalent thereof, and (y) that derives less than 90% of its income from the
Knowing their estimated costs and profit requirements the arbitrageur determines a minimum difference they need between the futures’ prices and the spot price before they will enter the market. They then monitor the price difference between Bitcoin futures and the Bitcoin exchanges and if large enough they act to profit on that gap.  For example, if a specific Bitcoin future (e.g., February contract) is trading sufficiently higher than the current Bitcoin exchange price they will short that Bitcoin future and hedge their position by buying Bitcoins on the exchange. At that point, if they have achieved trade prices within their targets, they have locked in a guaranteed profit. They will hold those positions until contract expiration (or until they can cover their short futures and sell Bitcoins at a profit).

Cryptocurrency is based on knowledge sharing on a distributed platform. The entire transactional history is for everyone to see. One blockchain is one thread of transaction. One unit or one block stores many transactions. The size of the block is 1MB and generally stores around 1000 to 2000 transactions. The data entered cannot be altered, nor can it be removed, enabling a system of complete transparency and trust. The entire money flow for the working model is beyond the traditional practices of controlling tax rates, credit usage, and money supply in the market.
The Advisor, its principals, officers and employees (and members of their families) and affiliates may participate directly or indirectly as investors in the Advisor’s clients, such as the Funds. Thus the Advisor may recommend to clients the purchase or sale of securities in which it, or its officers, employees or related persons have a financial interest. The Advisor may give advice and take actions in the performance of its duties to its clients that differ from the advice given or the timing and nature of actions taken, with respect to other clients’ accounts and/or employees’ accounts that may invest in some of the same securities recommended to clients.
•   Market Price Variance Risk — Fund shares are listed for trading on the [                    ] Exchange and can be bought and sold in the secondary market at market prices. The market price of shares will fluctuate in response to changes in the value of the Fund’s holdings, supply and demand for shares and other market factors. ProShare Advisors cannot predict whether shares will trade above, below or at a price equal to the value of the Fund’s holdings. Given the fact that shares can be created and redeemed in Creation Units, as defined below, ProShare Advisors believes that large discounts or premiums to the value of the Fund’s holdings should not be sustained. The Fund’s investment results are measured based upon the daily NAV of the Fund. Investors purchasing and selling shares in the secondary market may not experience investment results consistent with those experienced by Authorized Participants creating and redeeming directly with the Fund. To the extent that exchange specialists, market makers, Authorized Participants, or other participants are unavailable or unable to trade the Fund’s shares and/or create or redeem Creation Units, trading spreads and the resulting premium or discount on the Fund’s shares may widen and the Fund’s shares may possibly be subject to trading halts and/or delisting.
The Funds may enter into swap agreements to gain exposure to an underlying asset without actually purchasing such asset, or to hedge a position including in circumstances in which direct investment is restricted for legal reasons or is otherwise impracticable. Swap agreements are two-party contracts entered into primarily by institutional investors for periods ranging from a day to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on a particular pre-determined investment or instrument. The gross return to be exchanged or “swapped” between the parties is calculated with respect to a “notional amount,” e.g., the return on or increase in value of a particular dollar amount invested in a “basket” of securities or an ETF representing a particular index or group of securities.

The introduction of futures didn't lead to a wave of hedge-fund money shorting bitcoin. It led to retail and institutional money going long bitcoin. We talked last week about the spread between Cboe's bitcoin futures price and the actual price of bitcoin, which was wider than $1,000 for a while. The spread has tightened considerably -- as of 8:15 a.m. today, the CME futures traded at $18,585, Cboe futures at $18,670, and spot bitcoin at about $18,245, for a spread of about 2 percent -- but it still exists. Why would you pay more for a synthetic bitcoin in a month than you would for an actual bitcoin today? The answer, presumably, is that the synthetic bitcoin is more valuable to you: You want bitcoin exposure, but you'd prefer to get it through a standardized contract on a regulated exchange that settles in dollars. 
influence the price of Bitcoin and Bitcoin Instruments. In particular, it is possible that the price of the Bitcoin Instruments subsequent to a “fork” may be linked to the price of bitcoin on only one of the resulting Bitcoin Networks, rather than the aggregate price of bitcoin on all resulting Bitcoin Networks. The CFE and CME have announced different protocols for addressing forks.

Making money arbitraging bitcoin futures can be extremely simple. Futures contracts typically trade at a premium, and all you have to do, starting with USD, is buy bitcoin at Spot price and sell futures of the same amount at premium price. Then just wait until expiration to make your arb profit in bitcoin (which you can then put in USD). Whether it's a weekly, monthly, quarterly, or any futures contract, as long as it's in a premium, you lock in the sale price and earn the arbitrage profit.