If you want to speculate on the price of a cryptocurrency then the use of a Contract for Difference (CFD) is an option to consider. You won’t actually own the cryptocurrency, which means you don’t face the hassle and hurdles of trying to buy via one of the unregulated exchanges. Instead, a CFD is a financial instrument which allows you to speculate on price movements.

There are so many hoops to jump through to set up for mining and each coin has its quirks. The power of your machine and graphix card and your power consumption are all important. My friend mined for 8month Eth and only made couple of hundred bucks by time you subtract power useage etc. He already had a powerful machine used in film industry for video graphix just sitting around so he thought he’d put it to use over that time for a laugh and see what happened. It took many hours messing around to set up and occassionally nursing it over that period. Of course he had to use his machine also occassionally which compromised the performance.

•   Short Sale Exposure Risk — The Fund seeks inverse or “short” exposure through short positions in bitcoin futures contracts and other financial instruments. This will cause the Fund to be exposed to certain risks associated with selling assets short. These risks include, under certain market conditions, an increase in the volatility and decrease in the liquidity of the asset underlying the short position, which may lower the Fund’s return, result in a loss, have the effect of limiting the Fund’s ability to obtain inverse exposure through financial instruments such as swap agreements and futures contracts, or require the Fund to seek inverse exposure through alternative investment strategies that may be less desirable or more costly to implement. To the extent that, at any particular point in time, the assets underlying the short position may be thinly traded or have a limited market, including due to regulatory action, the Fund may be unable to meet its investment objective due to a lack of available securities or counterparties. During such periods, the Fund’s ability to issue additional Creation Units may be adversely affected. Obtaining inverse exposure through these instruments may be considered an aggressive investment technique. Inverse exposure must be actively managed in order to keep the Fund fully invested. See “Compounding Risk” above for an explanation of how this impacts performance
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 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.
For instance, last year, an ETF was rejected. This resulted in the boost of altcoins. Here, Kelly says that we saw Bitcoin outperform and altcoins prices go flat. Cryptocurrencies such as Ethereum [ETH] and XRP [XRP] have been flat due to all the money flowing into Bitcoin. In case of an ETF rejection or even delay, a heavy amount of money will flow out of Bitcoin and into the others.
An increase in cryptocurrency mining increased the demand of graphics cards (GPU) in 2017.[49] Popular favorites of cryptocurrency miners such as Nvidia’s GTX 1060 and GTX 1070 graphics cards, as well as AMD’s RX 570 and RX 580 GPUs, doubled or tripled in price – or were out of stock.[50] A GTX 1070 Ti which was released at a price of $450 sold for as much as $1100. Another popular card GTX 1060's 6 GB model was released at an MSRP of $250, sold for almost $500. RX 570 and RX 580 cards from AMD were out of stock for almost a year. Miners regularly buy up the entire stock of new GPU's as soon as they are available.[51]

No Independent Trustee (or an immediate family member thereof) had any direct or indirect interest, the value of which exceeded $120,000, in the Advisor, the principal underwriter of the Trust, or any entity controlling, controlled by or under common control with the Advisor or the principal underwriter of the Trust (not including registered investment companies) during the two most recently completed calendar years.
and other factors. Thus, to the extent a Fund invests in swaps that use an ETF as the reference asset, that Fund may be subject to greater correlation risk and may not achieve as high a degree of correlation with its index as it would if the Fund used only swaps on the underlying index. The Advisor, under the supervision of the Board of Trustees, is responsible for determining and monitoring the liquidity of the Funds’ transactions in swap agreements.
Amounts not distributed on a timely basis in accordance with a prescribed formula are subject to a nondeductible 4% excise tax at the Fund level. To avoid the tax, each Fund must distribute during each calendar year an amount generally equal to the sum of (1) at least 98% of its ordinary income (not taking into account any capital gains or losses) for the calendar year, (2) at least 98.2% of its capital gains in excess of its capital losses (adjusted for certain ordinary losses) for a one-year period generally ending on October 31
You might buy in to your Ethereum position at $1000, you set your sell position $1300. Your sell order could take days, weeks, months, years or till the end of time to be filled. Once it has been filled, you then take that profit and you roll it over in to a new buy over at, say, $1100. Choosing good targets for your buy and sell orders is crucial if you want to be a successful swing trader but overall swing trading cryptocurrency is pretty easy – set your orders and then just wait.
These days, all of the BTC/USD contracts trading at active futures markets are inverse, as mentioned in the beginning of this guide. The only differences between the exchanges is how they trigger liquidations and the procedure for handling margin calls. They all use Bitcoin as the currency, of course, and you can use the table below for a basic feature comparison:

The longest redemption cycle for a Fund is a function of the longest redemption cycle among the countries whose stocks comprise the Funds. Under certain conditions, a Fund may pay redemption proceeds more than seven days after the tender of a Creation Unit for redemption, but generally a Fund will not take more than fourteen calendar days from the date of the tender to pay redemption proceeds.

During the fiscal year ended May 31, 2017, the Advisor recouped $161,605 from UltraPro S&P 500 Fund pursuant to an Investment Advisory Agreement and the Expense Limitation Agreement between the Advisor and the Trust, on behalf of the Fund. During the fiscal year ended May 31, 2016, the Advisor recouped $155,882 from the UltraPro S&P 500 Fund pursuant to an Investment Advisory Agreement and the Expense Limitation Agreement between the Advisor and the Trust, on behalf of the Fund. During the fiscal year ended May 31, 2015, the Advisor recouped $259,539 from the UltraPro S&P 500 Fund pursuant to an Investment Advisory Agreement and the Expense Limitation Agreement between the Advisor and the Trust, on behalf of the Fund.
As of September 16, 2017, the Trustees and officers of the Trust, as a group, owned outstanding shares that entitled them to give voting instructions with respect to less than one percent of the shares of any series of the Trust; except that Mr. Michael L. Sapir owned more than 25% of the outstanding shares of ProShares S&P 500 Ex-Financials ETF and ProShares S&P 500 Ex-Health Care ETF.
In order to qualify for the withholding exemptions for interest-related and short term capital gain dividends, a foreign shareholder is required to comply with applicable certification requirements relating to its non-U.S. status (including, in general, furnishing the applicable W-8 form or substitute form). In the case of shares held through an intermediary, the intermediary may withhold even if the Fund reports all or a portion of a payment as an interest-related or short-term capital gain dividend to shareholders. Foreign shareholders should consult their tax advisors or intermediaries, as applicable, regarding the application of these rules to their accounts.
Daily access to the PCF and IOPV file is permitted (i) to certain personnel of those service providers that are involved in portfolio management and providing administrative, operational, or other support to portfolio management, including Authorized Participants, and (ii) to other personnel of the Advisor and the Funds’ distributor, administrator, custodian and fund accountant who are involved in functions which may require such information to conduct business in the ordinary course.
  •   A new competing digital asset may pose a challenge to bitcoin’s current market dominance, resulting in a reduction in demand for bitcoin, which could have a negative impact on the price of bitcoin. It is possible that other digital currencies and trading systems could become more widely accepted and used than bitcoin. The rise of such currencies could lead to a reduction in demand for bitcoin, which could have a negative impact on the price of bitcoin.
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.
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. 
The Fund is an actively managed exchange traded fund. The Fund seeks to achieve its investment objective by investing substantially all of its assets in a combination of (i) the equity securities of blockchain technology companies, (ii) bitcoin futures, options and swap contracts that provide exposure to the price movements of bitcoin (“Bitcoin Derivatives”) and (iii) bitcoin related securities, such as bitcoin linked exchange traded notes (“ETNs”), funds and trusts (“Bitcoin Securities”) (collectively, with Bitcoin Securities, “Bitcoin Investments”). The Fund targets a minimum of 30% exposure to Bitcoin Investments. The Fund’s other assets will be invested in the equity securities of blockchain technology companies — companies that the Fund’s investment advisor determines are well-positioned to benefit from blockchain technology. The securities of blockchain technology companies may be listed on U.S. or non-U.S. exchanges and must meet certain minimum capitalization and liquidity requirements. The Fund intends to concentrate its investment in blockchain technology companies and/or technology companies.
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.