•   Daily Position Limit Risk - Many U.S. futures exchanges limit the amount of fluctuation permitted in futures contract prices during a single trading day. Once the daily limit has been reached in a particular contract, no trades may be made that day at a price beyond that limit or trading may be suspended for specified periods during the trading day. In addition, these exchanges have established limits on the maximum amount of futures positions that any person may hold or control on such exchanges. These limits may restrict the amount of assets the Fund is able to invest in bitcoin futures contracts or have a negative impact on the price of such contracts. In order to comply with such limits, the Fund may be required to reduce the size of its outstanding positions or not enter into new positions that would otherwise be taken for the Fund. This could potentially subject the Funds to substantial losses or periods in which the Fund does not accept additional Creation Units.
A U.S. person, including a Fund, who owns (directly or indirectly) 10% or more of the total combined voting power of all classes of stock of a foreign corporation is a “U.S. Shareholder” for purposes of the CFC provisions of the Code. A CFC is a foreign corporation that, on any day of its taxable year, is owned (directly, indirectly, or constructively) more than 50% (measured by voting power or value) by U.S. Shareholders. Because of its investment in its Subsidiary, each Parent Fund is a U.S. Shareholder in a CFC. As a U.S. Shareholder, each Parent Fund is required to include in gross income for U.S. federal income tax purposes for each taxable year of the Fund its pro rata share of its CFC’s “subpart F income” for the CFC’s taxable year ending within the Fund’s taxable year whether or not such income is actually distributed by the CFC, provided that the foreign corporation has been a CFC for at least 30 uninterrupted days in its taxable year. Subpart F income generally includes interest, OID, dividends, net gains from the disposition of stocks or securities, net gains from transactions (including futures, forward, and similar transactions) in commodities, receipts with respect to securities loans, and net payments received with respect to equity swaps and similar derivatives. Subpart F income is treated as ordinary income, regardless of the character of the CFC’s underlying income. Net losses incurred by a CFC during a tax year do not flow through to an investing Fund and thus will not be available to offset income or capital gain generated from that Fund’s other investments. In addition, net losses incurred by a CFC during a tax year generally cannot be carried forward by the CFC to offset gains realized by it in subsequent taxable years. To the extent each Parent Fund invests in its Subsidiary and recognizes subpart F income in excess of actual cash distributions from such the Subsidiary, if any, it may be required to sell assets (including when it is not advantageous to do so) to generate the cash necessary to distribute as dividends to its shareholders all of its income and gains and therefore to eliminate any tax liability at the Fund level. Subpart F income also includes the excess of gains over losses from transactions (including futures, forward and other similar transactions) in commodities.

The identity and number of shares of the Deposit Securities required for a Portfolio Deposit for each Fund changes as rebalancing adjustments and corporate action events are reflected from time to time by ProShare Advisors with a view to the investment objective of the applicable Fund. The composition of the Deposit Securities may also change in response to adjustments to the weighting or composition of the securities constituting the relevant securities index, as applicable. The adjustments described above will reflect changes, known to ProShare Advisors on the date of announcement to be in effect by the time of delivery of the Portfolio Deposit, in the composition of the subject index being tracked by the relevant Fund, as applicable, or resulting from stock splits and other corporate actions. In addition, the Trust reserves the right to permit or require the substitution of an amount of cash (i.e., a “cash in lieu” amount) to be added to the Balancing Amount to replace any Deposit Security which may not be available in sufficient quantity for delivery or for other similar reasons. A Transaction Fee may be assessed on any “cash in lieu” amounts, as further described below under “Transaction Fees”. For the High Yield—Interest Rate Hedged, the Investment Grade—Interest Rate Hedged and the Short Term USD Emerging Markets Bond ETF, a minimum of 70% of the Deposit Securities must be delivered, unless such purchase is made on a cash-only basis.

  •   Large-Cap Company Investment Risk —The Fund invests in stocks of large-cap companies. Although returns on investments in large-cap companies are often perceived as being less volatile than the returns of companies with smaller market capitalizations, the return on large-cap securities could trail the returns on investments in smaller and mid-sized companies for a number of reasons. For example, large-cap companies may be unable to respond quickly to new competitive challenges, such as changes in technology, and also may not be able to attain the high growth rate of successful smaller companies.
(b) diversify its holdings so that, at the end of each quarter of a Fund’s taxable year (or by the end of the 30-day period following the close of such quarter), (i) at least 50% of the fair market value of the Fund’s assets is represented by cash and cash items (including receivables), U.S. government securities, the securities of other RICs and other securities, with such other securities limited, in respect of any one issuer, to a value not greater than 5% of the value of the Fund’s total assets and to an amount not greater than 10% of the outstanding voting securities of such issuer, and (ii) not greater than 25% of the value of its total assets is invested, including through corporations in which the Fund owns a 20% or more voting stock interest, in (x) the securities (other than U.S. government securities and the securities of other RICs) of any one issuer or of two or more issuers that the Fund controls and that are engaged in the same, similar or related trades or businesses, or (y) the securities of one or more qualified publicly traded partnerships (as defined below); and

There's a lot of ins and outs which can get confusing in arbitrage trading. We won't go into the technicals of why futures contracts trade at a premium to spot price. You can read a full explanation here. If it's not of interest to you, all you need to know is that there's a tendency, the further out in time the futures contract expires, for the premium to spot to be higher and higher in nominal percentage terms.