You could imagine the spread going the other way, though. If everyone really was clamoring to short bitcoin, and if the futures offered a more convenient way to do it than the bitcoin exchanges, then you'd expect the short sellers to pay a premium to short via futures. Instead of selling a bitcoin at $18,000 today, they'd be willing to sell a synthetic bitcoin for $17,500, paying the spread to an arbitrageur who was willing to do the actual shorting for them. But the fact that the spread is mostly positive, and that bitcoin's price has been mostly going up, suggests that the demand has mostly been for synthetic long positions, not short.

Were Centra's tokens securities? Well, yes, obviously. We talked last week about the Securities and Exchange Commission's enforcement action against Munchee, an initial coin offering vaguely similar to Centra's in that it featured "utility tokens" to be used in a blockchain ecosystem that did not yet exist, sold on promises of speculative returns. The SEC brusquely and correctly dismissed the notion that such "utility tokens" were not securities, and I suspect any court will agree. Also, while Centra occasionally remembered to call its tokens "utility-based tokens" and "not securities, shares or investments," it often forgot. From the complaint:
Short Term USD Emerging Markets Bond ETF; Crude Oil Strategy ETF; Inflation Expectations ETF; CDS Short North American HY Credit ETF and Short or Ultra Fixed Income ProShares Funds    2:30 p.m. (3:00 p.m., if transmitted by mail; except 4:00 p.m., if transmitted by mail on behalf of Short High Yield or Ultra High Yield) in order to receive that day’s closing NAV per Share
Interest Rate Swaps. Interest rate swaps, in their most basic form, involve the exchange by a Fund with another party of their respective commitments to pay or receive interest. For example, a Fund might exchange its right to receive certain floating rate payments in exchange for another party’s right to receive fixed rate payments. Interest rate swaps can take a variety of other forms, such as agreements to pay the net differences between two different interest indexes or rates, even if the parties do not own the underlying instruments. Despite their differences in form, the function of interest rate swaps is generally the same: to increase or decrease a Fund’s exposure to long- or short-term interest rates. For example, a Fund may enter into a swap transaction to preserve a return or spread on a particular investment or a portion of its portfolio or to protect against any increase in the price of securities the Fund anticipates purchasing at a later date.
The value of such Creation Unit for the S&P 500 Dividend Aristocrats ETF, the MSCI EAFE Dividend Growers ETF, the DJ Brookfield Global Infrastructure ETF, the Global Listed Private Equity ETF, the Large Cap Core Plus, the Hedge Replication ETF, the Merger ETF, the Inflation Expectations ETF, the CDS Short North American HY Credit ETF, the UltraPro Short Financial Select Sector ETF, the UltraShort FTSE Europe ETF, the UltraPro Financial Select Sector ETF, and the Ultra High Yield ETF as of each such Fund’s inception was $2,000,000.
CCC – An obligation rated ‘CCC’ is currently vulnerable to nonpayment, and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation. In the event of adverse business, financial, or economic conditions, the obligor is not likely to have the capacity to meet its financial commitment on the obligation.
Margin Call - when you run out of bitcoin on your account to cover the contract positions you have taken (your account value doesn't cover the Maintance Margin) you are officially rekt. Some exchanges like CryptoFacilities will merely notify you that you have to deposit more or reduce your positions to increase your margin. Others like BitMEX will liquidate you at this level where the exchange takes over your position to liquidate it into the market to prevent system loss.
Paul Krugman, Nobel Memorial Prize in Economic Sciences winner does not like bitcoin, has repeated numerous times that it is a bubble that will not last[110] and links it to Tulip mania.[111] American business magnate Warren Buffett thinks that cryptocurrency will come to a bad ending.[112] In October 2017, BlackRock CEO Laurence D. Fink called bitcoin an 'index of money laundering'.[113] "Bitcoin just shows you how much demand for money laundering there is in the world," he said.
Maybe one day our fiat money system will go under and be completely replaced by cryptocurrencies. We’re living in a digitalized world and the possibility of Bitcoin or any other major cryptocurrencies to replace the way we pay for the goods and services is not beyond the realms of possibility. However, as long as there are still profits to be made from Forex currency trading we encourage you to read our receipt for Forex trading success: How to Make Money Trading – 2 Keys to Success.
As we have seen above, a futures contract has an expiration date. This is the date on which you can purchase the ton of pork bellies for 1,000 USD – this is called a physical settlement. Alternatively, futures contracts can be settled with cash as well. In these contracts, you receive the difference between the current price of the underlying asset and the price in your contract as cash.
In cryptocurrency networks, mining is a validation of transactions. For this effort, successful miners obtain new cryptocurrency as a reward. The reward decreases transaction fees by creating a complementary incentive to contribute to the processing power of the network. The rate of generating hashes, which validate any transaction, has been increased by the use of specialized machines such as FPGAs and ASICs running complex hashing algorithms like SHA-256 and Scrypt.[38] This arms race for cheaper-yet-efficient machines has been on since the day the first cryptocurrency, bitcoin, was introduced in 2009.[38] With more people venturing into the world of virtual currency, generating hashes for this validation has become far more complex over the years, with miners having to invest large sums of money on employing multiple high performance ASICs. Thus the value of the currency obtained for finding a hash often does not justify the amount of money spent on setting up the machines, the cooling facilities to overcome the enormous amount of heat they produce, and the electricity required to run them.[38][39]
Each Fund has adopted certain investment restrictions as fundamental policies that cannot be changed without a “vote of a majority of the outstanding voting securities” of the Fund. The phrase “majority of outstanding voting securities” is defined in the 1940 Act as the lesser of: (i) 67% or more of the shares of the Fund present at a duly-called meeting of shareholders, if the holders of more than 50% of the outstanding shares of the Fund are present or represented by proxy; or (ii) more than 50% of the outstanding shares of the Fund. (All policies of a Fund not specifically identified in this Statement of Additional Information or its Prospectus as fundamental may be changed without a vote of the shareholders of the Fund.) For purposes of the following limitations, all percentage limitations apply immediately after a purchase or initial investment.
The ProShares Bitcoin/Blockchain Strategy ETF contains portfolio investments that are primarily listed on foreign markets. To the extent the Fund’s portfolio investments trade in foreign markets on days when the Fund is not open for business or when the primary exchange for its shares is not open, the value of the Fund’s assets may vary on days when shareholders may not be able to purchase or sell Fund shares and Authorized Participants may not be able to create or redeem Creation Units. Also, certain portfolio investments may not be traded on days the Fund is open for business.
The NAV of each Fund is typically determined each business day at 3:00 p.m., Eastern Time on days when                    is open for trading. The [            ] Exchange is open every week, Monday through Friday, except when the following holidays are celebrated: New Year’s Day, Martin Luther King, Jr. Day (the third Monday in January), Presidents’ Day (the third Monday in February), Good Friday, Memorial Day (the last Monday in May), Independence Day, Labor Day (the first Monday in September), Thanksgiving Day (the fourth Thursday in November) and Christmas Day. An Exchange may close early on the business day before each of these holidays and on the day after Thanksgiving Day. Exchange holiday schedules are subject to change without notice. If the exchange or market on which a Fund’s investments are primarily traded closes early, the NAV may be calculated prior to its normal calculation time. Creation/ redemption transaction order time cutoffs would also be accelerated.

!! WARNING !!! Note that on CryptoFacilities each contract is denominated by 1 BTC. So if you bought a fraction of BTC you can NOT perform a perfect hedge of the value. If you round the BTC you bought with start capital down, you will have slight overexposure LONG with the left-over BTC. If you round up and short an extra contract, you will have slight overexposure SHORT.