In order to make sure that you actually have money in your margin account to settle the difference with Mortimer every day, you are required to put up an initial margin at the beginning of the contract. A lower sum, the so-called minimum margin or maintenance margin, is also defined by the broker. If the money in your margin account falls from the initial margin to the maintenance margin, it triggers a margin call: The broker requests you to fill up your margin account to at least the initial margin (of course, you may also put up more).

Typically exchanging is done through matching the buy and sell orders placed on the system of the exchange. The sell orders are made at an offer price (or ask) while the buy order (or bid) is made to buy bitcoins. It is similar to buying stocks online where you need to enter the desired price (or market price) for buy/sell along with the quantity. These orders enter the order book and are removed once the exchange transaction is complete.
For each of the following Funds that hold Non-U.S. Investments: the DJ Brookfield Global Infrastructure ETF; the Global Listed Private Equity ETF; the MSCI EAFE Dividend Growers ETF; the MSCI Europe Dividend Growers; the Short Term USD Emerging Markets Bond ETF; and the Merger ETF (each a “Global Fund” and collectively the “Global Funds”), when a purchase order is placed, the Distributor will inform the Advisor and the Custodian. The Custodian shall cause local sub-custodians of the applicable Global Fund to maintain an account into which the Authorized Participant shall deliver, on behalf of itself or the party on whose behalf it is acting, the Deposit Securities “free of payment,” with any appropriate adjustments as advised by the Trust, in accordance with the terms and conditions applicable to such account in such jurisdiction. If applicable, the sub-custodian(s) will confirm to the Custodian that the required Deposit Securities have been delivered and the Custodian will notify the Advisor and Distributor. The Authorized Participant must also make available to the Custodian no later than 12:00 noon Eastern Time (or earlier in the event that the relevant Exchange or the relevant bond markets close early) by the second Business Day after the order is deemed received through the Federal Reserve Bank wire transfer system, immediately available or same day funds in U.S. dollars estimated by the Trust to be sufficient to pay the Balancing Amount next determined after acceptance of the purchase order, together with any applicable Transaction Fees. For Global Funds, the Index Receipt Agent will not make available through the NSCC on each Business Day, the list of the names and the required number of shares of each Deposit Security to be included in the current Portfolio Deposit.
In cryptocurrency networks, mining is a validation of transactions. For this effort, successful miners obtain new cryptocurrency as a reward. The reward decreases transaction fees by creating a complementary incentive to contribute to the processing power of the network. The rate of generating hashes, which validate any transaction, has been increased by the use of specialized machines such as FPGAs and ASICs running complex hashing algorithms like SHA-256 and Scrypt.[38] This arms race for cheaper-yet-efficient machines has been on since the day the first cryptocurrency, bitcoin, was introduced in 2009.[38] With more people venturing into the world of virtual currency, generating hashes for this validation has become far more complex over the years, with miners having to invest large sums of money on employing multiple high performance ASICs. Thus the value of the currency obtained for finding a hash often does not justify the amount of money spent on setting up the machines, the cooling facilities to overcome the enormous amount of heat they produce, and the electricity required to run them.[38][39]
The NAV of each Fund is typically determined each business day at 3:00 p.m., Eastern Time on days when                    is open for trading. The [            ] Exchange is open every week, Monday through Friday, except when the following holidays are celebrated: New Year’s Day, Martin Luther King, Jr. Day (the third Monday in January), Presidents’ Day (the third Monday in February), Good Friday, Memorial Day (the last Monday in May), Independence Day, Labor Day (the first Monday in September), Thanksgiving Day (the fourth Thursday in November) and Christmas Day. An Exchange may close early on the business day before each of these holidays and on the day after Thanksgiving Day. Exchange holiday schedules are subject to change without notice. If the exchange or market on which a Fund’s investments are primarily traded closes early, the NAV may be calculated prior to its normal calculation time. Creation/ redemption transaction order time cutoffs would also be accelerated.
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.