In February 2014 the world's largest bitcoin exchange, Mt. Gox, declared bankruptcy. The company stated that it had lost nearly $473 million of their customers' bitcoins likely due to theft. This was equivalent to approximately 750,000 bitcoins, or about 7% of all the bitcoins in existence. The price of a bitcoin fell from a high of about $1,160 in December to under $400 in February.[85]
Certain Funds expect to invest in exchange-traded funds, including exchange-traded funds registered under the 1940 Act (“Underlying ETFs”). Some such Underlying ETFs will be treated as regulated investment companies for federal income tax purposes (each such Underlying ETF, an “Underlying RIC”). In such cases, a Fund’s income and gains will normally consist, in whole or part, of dividends and other distributions from the Underlying RICs and gains and losses on the disposition of shares of the Underlying RICs. The amount of income and capital gains realized by a Fund and in turn a Fund’s shareholders in respect of the Fund’s investments in Underlying RICs may be greater than such amounts would have been had the Fund invested directly in the investments held by the Underlying RICs, rather than in the shares of the Underlying RICs. Similarly, the character of such income and gains (e.g., long-term capital gain, eligibility for the dividends-received deduction, etc.) will not necessarily be the same as it would have been had the Fund invested directly in the investments held by the Underlying RICs.
Most traders who do not have a plan for trading blindly will be eliminated in the near future. As a transaction, bitcoin trading is no different from other underlying objects, such as stock futures. An effective trading strategy is essential in order to make a steady profit in this market. Stop the loss of profits, homeopathy, light warehouse is the key. To strictly implement these trading plan, use the program trading is very effective, program trading my first contact with bitcoin is BotVS quantification in the know the platform to see the column introduced bitcoin hedging strategy is inspired by. Later, I tried to write some trading strategies and use them on firm exchanges. Accumulated a lot of bitcoin trading experience. I’m still bullish on bitcoin, which was a great invention in the twenty-first Century.
If you want to do scalping, then shorter-term expiree contracts that settle really soon would be fine. Keep in mind, the normal state of futures markets is "contango", which means that longer dated contracts will have a premium to the current spot rate, to reflect the interest rate differential and time preference.  This means you will see Weeklies maybe with a $1-2 preium and Quarterlies (assuming they expire months from now) with a $5-8 premium.  As an example we have Quarterlies contracts right now at OKCoin that settle on December 25. So we're just starting December now, that means that even though these are "Quarterlies" contracts by classification, they are expiring not 3 months from now, but 1 month from now. Don't mix up the settlement expiration date with the naming convention. 
JUNK BONDS. “Junk Bonds” generally offer a higher current yield than that available for higher-grade issues. However, lower-rated securities involve higher risks, in that they are especially subject to adverse changes in general economic conditions and in the industries in which the issuers are engaged, to changes in the financial condition of the issuers and to price fluctuations in response to changes in interest rates. During periods of economic downturn or rising interest rates, highly leveraged issuers may experience financial stress that could adversely affect their ability to make payments of interest and principal and increase the possibility of default. In addition, the market for lower-rated debt securities has expanded rapidly in recent years, and its growth paralleled a long economic expansion. At times in recent years, the prices of many lower-rated debt securities declined substantially, reflecting an expectation that many issuers of such securities might experience financial difficulties. As a result, the yields on lower-rated debt securities rose dramatically, but the higher yields did not reflect the value of the income stream that holders of such securities expected. Rather, the risk that holders of such securities could lose a substantial portion of their value as a result of the issuers’ financial restructuring or default. There can be no assurance that such declines will not recur. The market for lower-rated debt issues generally is thinner and less active than that for higher quality securities, which may limit each Fund’s ability to sell such securities at fair value in response to changes in the economy or financial markets. Adverse publicity and investor perceptions, whether or not based on fundamental analysis, may also decrease the values and liquidity of lower-rated securities, especially in a thinly traded market. Changes by recognized rating services in their rating of a fixed income security may affect the value of these investments. Each Fund will not necessarily dispose of a security when its rating is reduced below the rating it had at the time of purchase. However, the Advisor will monitor the investment to determine whether continued investment in the security will assist in meeting each Fund’s investment objective.
Homero Josh Garza, who founded the cryptocurrency startups GAW Miners and ZenMiner in 2014, acknowledged in a plea agreement that the companies were part of a pyramid scheme, and pleaded guilty to wire fraud in 2015. The U.S. Securities and Exchange Commission separately brought a civil enforcement action against Garza, who was eventually ordered to pay a judgment of $9.1 million plus $700,000 in interest. The SEC's complaint stated that Garza, through his companies, had fraudulently sold "investment contracts representing shares in the profits they claimed would be generated" from mining.[88]
  •   Ownership of bitcoin is pseudonymous and the supply of accessible bitcoins is unknown. There is no registry showing which individuals or entities own bitcoin or the quantity of bitcoin that is owned by any particular person or entity. It is possible, that a small group of early bitcoin adopters hold a significant proportion of the bitcoin that has been thus far created. There are no regulations in place that would prevent a large holder of bitcoin from selling its bitcoins, which could depress the price of bitcoin and have an adverse effect on an investment in the Fund.
  •   Risks Associated with Bitcoin – The Fund is exposed to risks associated with bitcoin. Investing in or gaining exposure to Bitcoin may provide the Fund with increased risk. Various global factors may negatively impact the Fund’s performance including legal, regulatory, political, social, regional and economic events. These risks, which could have a negative impact on the performance of the Fund and the trading price of Fund shares, include the following:
It can often be confusing to traders who are using multiple futures exchanges with different contract types -- inverse and qunato, dailies or quarterlies, 5x or 100x -- so people wonder: what should I trade? Well, it depends on what your goals are. If you are trying to do a little hedge for a medium term, you would want to use a quarterlies expiration contract instead, because otherwise you'd have to reopen shorter-term contracts after they expire and settle. 
With the increased use of technologies such as the Internet and the dependence on computer systems to perform necessary business functions, the Funds and the digital assets that underline the bitcoin futures contracts in which the Funds invest are susceptible to operational and information security risk. The digital nature of bitcoins and the irreversible nature of bitcoin transactions makes bitcoin an attractive target for theft, hacking and other cyber-attacks. In general, cyber incidents can result from deliberate attacks or unintentional events. Cyber-attacks include, but are not limited to gaining unauthorized access to digital systems for purposes of misappropriating assets such as bitcoin or other cryptocurrencies or gaining access to sensitive information, corrupting data, or causing operational disruption. Cyber-attacks may also be carried out in a manner that does not require gaining unauthorized access, such as causing denial-of-service attacks on websites. Such events have historically correlated with a drop in the price of bitcoin, which may adversely affect your investment in a Fund. Cyber security failures or breaches of a Fund’s third party service provider (including, but not limited to, index providers, the administrator and transfer agent) or the issuers of the bitcoin futures contracts in which the Funds invest, have the ability to cause disruptions and impact business operations, potentially resulting in financial losses, the inability of a Fund’s shareholders to transact business, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, and/or additional compliance costs. In addition, substantial costs may be incurred in order to prevent any cyber incidents in the future. The Funds their service providers, counterparties and other market participants on which the Funds rely could be negatively impacted as a result. While the Funds have established business continuity plans and systems to prevent such cyber-attacks, there are inherent limitations in such plans and systems including the possibility that certain risks have not been identified.
Assume it is January 3, 2015. Bob and Ann both want to trade at Bitcoin Futures Exchange (BFE). BFE offers 3 different contracts: one expiring and settling on Friday January 9 ('weekly'), another expiring Friday January 16th ('biweekly'), and finally one expiring in March 27 ('quarterly').  Each contract is worth 1 bitcoin notionally.  BFE has a policy that traders have to put 20% of margin down to enter a trade, so Bob and Ann deposit 0.2btc to their BFE accounts as they only want to trade 1 contract.

Each Fund may engage in transactions in index options listed on national securities exchanges or traded in the OTC market as an investment vehicle for the purpose of realizing the Fund’s investment objective. The exercising holder of an index option receives, instead of the asset, cash equal to the difference between the closing level of the index and the exercise price of the option. Some index options are based on a broad market index such as the Standard & Poor’s (“S&P”) 500® Index, the New York Stock Exchange, Inc. (“NYSE”) Composite Index or on a narrower index such as the Philadelphia Stock Exchange Over-the-Counter Index. Options currently are traded on the Chicago Board Options Exchange, the NYSE Amex Options and other exchanges (collectively, “Exchanges”). Purchased OTC options and the cover for written OTC options will be subject to the relevant Fund’s 15% limitation on investment in illiquid securities. See “Illiquid Securities” below. When required by law, a Fund will segregate liquid assets in an amount equal to the value of the Fund’s total assets committed to the consummation of such options. Obligations under options so covered will not be considered senior securities for purposes of a Fund’s investment restriction concerning senior securities.
DTC may determine to discontinue providing its service with respect to Shares at any time by giving reasonable notice to the Trust and discharging its responsibilities with respect thereto under applicable law. Under such circumstances, the Trust shall take action either to find a replacement for DTC to perform its functions at a comparable cost or, if such a replacement is unavailable, to issue and deliver printed certificates representing ownership of Shares, unless the Trust makes other arrangements with respect thereto satisfactory to the Exchange. In addition, certain brokers may make a dividend reinvestment service available to their clients. Brokers offering such services may require investors to adhere to specific procedures and timetables in order to participate. Investors interested in such a service should contact their broker for availability and other necessary details.
•   Portfolio Turnover Risk — In seeking to meet its investment objective, the Fund may incur high portfolio turnover to manage the Fund’s investment exposure. Additionally, active market trading of the Fund’s shares may cause more frequent creation or redemption activities that could, in certain circumstances, increase the number of portfolio transactions. High levels of transactions increase brokerage and other transaction costs and may result in increased taxable capital gains.
The term altcoin has various similar definitions. Stephanie Yang of The Wall Street Journal defined altcoins as "alternative digital currencies,"[25] while Paul Vigna, also of The Wall Street Journal, described altcoins as alternative versions of bitcoin.[26] Aaron Hankins of the MarketWatch refers to any cryptocurrencies other than bitcoin as altcoins.[27]

•   Compounding Risk — In the course of managing the Fund’s investments, ProShare Advisors will need to periodically adjust the Fund’s holdings in order to maintain investment exposure approximately equivalent to the Fund’s assets. This process entails obtaining additional inverse exposure as the Fund experiences gains, and reducing inverse exposure as the Fund experiences losses. The higher the volatility of the bitcoin futures contracts in which the Fund invests, the more such rebalancing can adversely affect the Fund’s performance.
The Funds may invest in equity securities. The market price of securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. Securities may decline in value due to factors affecting securities markets generally or particular industries represented in the securities markets. The value of a security may decline due to general market conditions not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. A security’s value may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. The value of a security may also decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services. Equity securities generally have greater price volatility than fixed income securities, and the Funds are particularly sensitive to these market risks.
While “physical” delivery of Bitcoins as part of a futures contract would certainly be possible it raises regulatory and security issues in today’s environment where the cybercurrency exchanges are mostly unregulated, somewhat unreliable, and theft due to security hacks is distressingly common.  By selecting cash settlement the CME and Cboe completely avoid the transfer of custody issues and shift those problems to somebody else—namely the market makers and arbitrageur.
Currently, Bitcoin futures have very high margin requirements. The Cboe requires 40% of the notional amount for maintenance margin, the CME requires 43%. Your broker will likely require more than that. The culprit behind these high requirements is Bitcoin’s high volatility—until that calms down the exchanges will protect themselves by requiring a bunch of up-front money. If you don’t come up with the money for a margin call they want to close out your position without leaving a negative balance.
Currently there are a several digital asset trading platforms that provide investors with forms of derivative products such as futures, so one could estimate and synthesize the discrete futures curve from the averages of various curves. MVIS research used BitMEX, OKCoin, CryptoFacilities, and BTCC as sources, to construct and approximate bitcoin futures curve based on non-U.S. bitcoin futures trading on these exchanges.
Each Fund intends to use, on a regular basis, leveraged investment techniques in pursuing its investment objective. Leverage exists when a Fund achieves the right to a return on a capital base that exceeds the Fund’s assets. Utilization of leverage involves special risks and should be considered to be speculative. Specifically, leverage creates the potential for greater gains to Fund shareholders during favorable market conditions and the risk of magnified losses during adverse market conditions. Leverage is likely to cause higher volatility of the NAVs of these Funds’ Shares. Leverage may also involve the creation of a liability that does not entail any interest costs or the creation of a liability that requires the Fund to pay interest which would decrease the Fund’s total return to shareholders. If these Funds achieve their investment objectives, during adverse market conditions, shareholders should experience a loss greater than they would have incurred had these Funds not been leveraged.
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.
As for why you should buy a put option instead of the asset itself, the answer is simple. By buying the asset itself, you can never profit from falling prices. With put options you can, simply because their value rises as the price of the underlying stock is falling. In addition to this feature, they offer the same kind of potential for leverage that calls options do, as described above. The price of put options is calculated in a similar manner, but with the important difference being that the intrinsic value is calculated as a predetermined price of the option minus the current market price of the asset – not the other way round as is the case for call options.