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.
The Funds may enter into swap agreements to gain exposure to an underlying asset without actually purchasing such asset, or to hedge a position including in circumstances in which direct investment is restricted for legal reasons or is otherwise impracticable. Swap agreements are two-party contracts entered into primarily by institutional investors for periods ranging from a day to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on a particular pre-determined investment or instrument. The gross return to be exchanged or “swapped” between the parties is calculated with respect to a “notional amount,” e.g., the return on or increase in value of a particular dollar amount invested in a “basket” of securities or an ETF representing a particular index or group of securities.
Traders A and B in the previous example are hedgers. However, futures contracts, once they exist, can also be bought and sold in their own right. This is where futures get interesting for speculators. Say that Speculator X believes the price of a ton of pork belly will rise to 1,200 USD in 3 months’ time, so buying the futures contract at 1,000 USD is a good deal. He can then sell the contract to bacon producers who want to buy pork bellies at 1,000 USD. The option to buy at a specified price in the future is known as a call option. The price of call options rise when traders assume that the price of the underlying asset will rise.
For each intervening holiday in the applicable foreign market that is not a holiday observed by the U.S. equity markets, the redemption settlement cycle will be extended by the number of days of such intervening holiday. In addition to holidays, other unforeseeable closings in a foreign market, including due to regulatory action, may also prevent a Fund from delivering securities within the normal settlement period.
Bob's transaction confirms first so he goes on BFE and looks at the contract selections. He wants to trade on the January 9 expiration contract. The orderbook is empty and Bob wants to go long (profit off an increase in bitcoin). Since there are no offers available, he places a limit order in the orderbook for a bid at 400 of 1 contract, using his 0.2btc as collateral for the position.

The value of such Creation Unit for the MSCI Europe Dividend Growers ETF, the S&P 500 Ex-Energy ETF, the S&P 500 Ex-Financials ETF, the S&P 500 Ex-Health Care ETF, the S&P 500 Ex-Technology ETF, High Yield—Interest Rate Hedged, the Investment Grade—Interest Rate Hedged, the Short Term USD Emerging Markets Bond ETF, the UltraPro Short S&P500® ETF, the UltraPro Short QQQ® ETF, the UltraPro Short Dow30SM ETF, the UltraPro Short MidCap400 ETF, the UltraPro Short Russell2000 ETF, the Short High Yield ETF, the UltraPro S&P500® ETF, the UltraPro QQQ® ETF, the UltraPro Dow30SM ETF, the UltraPro MidCap400 ETF and the UltraPro Russell2000 ETF as of each such Fund’s inception was $4,000,000.

Speculating and hedging bitcoin with futures has never been easier. Spot has lower leverage which means you have to risk more of your capital with exchanges. Margin fees are very expensive on Bitfinex and Kraken when you are borrowing funds and paying up to 0.1% per day to be in a position. Futures contracts on the other hand have no holding fees associated. You pay a fee to enter the contract, and you pay a fee to exit the contract. Your profit or loss comes from the change in the price you pay.
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]
Note that any losses on the bitcoin position is offset by the short position in the Jan XBT Futures contract.  Because Jan XBT was trading at a $1,000 premium to spot bitcoin, the profit for this trade is equal to that difference.  Now, keep in mind if bitcoin doubles between now and January 17 settlement the maximum profit is $1000.  Larry is giving up some upside to assure a return of $1000.
impede the functionality of the Bitcoin Network and adversely affect the price of bitcoin. Any technical disruptions or regulatory limitations that affect Internet access may have an adverse effect on the Bitcoin Network, the price of bitcoin and the bitcoin futures contracts in which the Fund invests. In addition to technical disruptions such as cyber-attacks, the potential elimination of the net neutrality regulations in the U.S. may have a negative impact on bitcoin and the Bitcoin ecosystem.
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.