In a futures market, if the price is $500/BTC, an investor needs to buy 50 futures contracts, each worth $10. If an investor wishes to open a positive position then he goes long with “buy" contracts, and if he decides to open a negative position, he goes short with “sell” contracts. An investor’s position can be either positive or negative for the same instrument. (For more, see: Bitcoin Mass Hysteria: The Disaster that Brought Down Mt. Gox.)
The Distribution and Service Plan and Distribution and Service Agreements will remain in effect for a period of one year and will continue in effect thereafter only if such continuance is specifically approved annually by a vote of the Trustees. All material amendments of the Distribution and Service Plan must also be approved by the Board. The Distribution and Service Plan may be terminated at any time by a majority of the Board or by a vote of a majority of the outstanding Shares, as defined under the 1940 Act, of the affected Fund. The Distribution and Service Agreements may be terminated at any time, without payment of any penalty, by vote of a majority of the Independent Trustees or by a vote of a majority of the outstanding Shares, as defined under the 1940 Act, of the affected Fund on not less than 60 days’ written notice to any other party to the Distribution and Service Agreements. The Distribution and Service Agreements shall terminate automatically if assigned. The Board has determined that, in its judgment, there is a reasonable likelihood that the Distribution and Service Plan will benefit the Funds and holders of Shares of the Funds. In the Board’s quarterly review of the Distribution and Service Plan and Distribution and Service Agreements, the Trustees will consider their continued appropriateness and the level of compensation and/or reimbursement provided therein.
This can serve two purposes; firstly, CFDs are a regulated financial product which means the brokers who offer them should be licensed by a regulatory authority. The brokers we review are all regulated by reputable financial regulatory bodies, offering varying degrees of protection for your money – from ensuring it is held in a segregated bank account to participation in compensation schemes should the broker become insolvent. There are, of course, criminal CFD brokers operating outside the law so you should do your homework before depositing!
Like any futures contract, trading in XBT futures is not suitable for all investors and involves the risk of loss. The risk of loss in XBT futures can be substantial. Market participants should, therefore, carefully consider whether such trading is suitable in light of their own circumstances and financial resources. For additional information regarding futures trading risks, see the Risk Disclosure Statement set forth in CFTC Regulation 1.55(b).

Jump up ^ "Bitcoin: The Cryptoanarchists' Answer to Cash". IEEE Spectrum. Archived from the original on 4 June 2012. Around the same time, Nick Szabo, a computer scientist who now blogs about law and the history of money, was one of the first to imagine a new digital currency from the ground up. Although many consider his scheme, which he calls “bit gold,” to be a precursor to Bitcoin
Important agents interacting with those prices are operating in one of three roles: individual speculator, market maker, or arbitrageur. A key role is market maker—a firm that has agreed to simultaneously act as both a buyer and seller for a specific security. When companies sign up for this role they agree to keep the bid/ask prices relatively close to each other—for example even if they aren’t keen on selling Bitcoins at the moment they can’t just set the ask price to an outrageous level. The agreed-upon maximum bid/ask ranges might be tied to market conditions (e.g., wider when deemed a “fast market”) and might allow time-outs but in general, the market maker agrees to act as a buffer between supply and demand.
In this guide we don't want to deal with social loss risk, so use the FCA-regulated, London-based bitcoin derivatives exchange CryptoFacilities. They offer contracts with 2% margin requirement (50x leverage) as well as a 15% margin requirement (6.5x leverage). They are 100% bitcoin based, but they don't accept US customers. Sign up here to get started: