Double spending means, as the name suggests, that a Bitcoin user is illicitly spending the same money twice. With physical currency, this isn't an issue: Once you hand someone a greenback $20 bill to buy a bottle of vodka, you no longer have it, so there's no danger you could use that same $20 to buy lotto tickets next door. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original."

But the rate is not expected to be kept: sometime in 2018-2019 Ethereum will be switched from Proof of Work to a new consensus algorithm under development, called Casper that is expected to be more efficient and require less mining subsidy. The exact method of issuance and which function it will serve is an area of active research, but what can be guaranteed now is that (1) the current maximum is considered a ceiling and the new issuance under casper will not exceed it (and is expected to be much less) and (2) whatever method is ultimately picked to issue, it will be a decentralized smart contract that will not give preferential treatment to any particular group of people and whose purpose is to benefit the overall health and security of the network.


A market order in this case would submit a buy order for XBT at the price of the lowest available sell order. Using the orderbook above, a market order for 0.5 XBT would purchase 0.5 XBT at $384.07 per XBT. If selling bitcoins, a market order would sell bitcoins for the highest available price based on the current buy orderbook—in this case $382.5.
A notable example of this was FBI’s shutdown of the ‘’Silk Road’’ marketplace. The website had over 10,000 products for sale, 70% of which were drugs that are illegal in most countries. Around 340 different varieties of drugs were offered on the site. The site functioned as an ‘’Ebay for drugs’’, connecting buyers with sellers and not doing any dealing themselves.
The Mid-Columbia Basin isn’t the only location where the virtual realm of cryptocurrency is colliding with the real world of megawatts and real estate. In places like China, Venezuela and Iceland, cheap land and even cheaper electricity have resulted in bustling mining hubs. But the basin, by dint of its early start, has emerged as one of the biggest boomtowns. By the end of 2018, according to some estimates, miners here could account for anywhere from 15 to 30 percent of all bitcoin mining in the world, and impressive shares of other cryptocurrencies, such as Ethereum and Litecoin. And as with any boomtown, that success has created tensions. There have been disputes between miners and locals, bankruptcies and bribery attempts, lawsuits, even a kind of intensifying guerrilla warfare between local utility crews and a shadowy army of bootleg miners who set up their servers in basements and garages and max out the local electrical grids.
It’s important to specify a time horizon for your investment—such as short term (7–14 days), medium term (1–2 months) or long-term (6–12 months). I don’t recommend trading on time horizons shorter than 7 days unless you have access to margin (you probably don’t) or have large amounts of money to play with; otherwise, the fees will be too high relative to the returns.
When it comes to finding the best bitcoin exchange things are not all that easy. Many of the best bitcoin exchanges to buy bitcoin are only recently online. This means that they have had little time to get the word out about their services and products. Most people coming to this page will be asking how to buy bitcoin online through a secure means. Well, here is a good starting point. 
The silence of the Chinese authorities was seen as a subtle acceptance signal by market participants. The situation didn’t last long however. On December 7th, The People’s Bank of China barred financial institutions from buying or selling virtual currency or Bitcoin related products. The Bank also demanded that businesses stop with the practice of pricing their products in Bitcoins. BTC/USD opened the day at $906.50 on BTC-E. After the news hit the wires, bitcoin prices crashed from to a low of $551 in only 9 hours, a fall of 39%.
HIGH RISK INVESTMENT WARNING: Trading foreign exchange and/or contracts for difference on margin carries a high level of risk, and may not be suitable for all investors. The possibility exists that you could sustain a loss in excess of your deposited funds and therefore, you should not speculate with capital that you cannot afford to lose. Before deciding to trade the products offered by BitcoinTradingWorld you should carefully consider your objectives, financial situation, needs and level of experience. You should be aware of all the risks associated with trading on margin. BitcoinTradingWorld provides general advice that does not take into account your objectives, financial situation or needs. The content of this Website must not be construed as personal advice. BitcoinTradingWorld recommends you seek advice from a separate financial advisor.

1. The blockchain is a ledger that keeps track of how much ‘stuff’ (ie BTC, ETH,…create your own currency if you wish) you have. Its the history of transactions. ‘Ethereum’ provides a platform for building contracts…if a contract’s conditions are met, then a transaction (whose rules and automation are agreed ahead of time) automatically occurs and the result of that transaction becomes a part of the ledger. Anyone will be able to see that an address (sellers’ public key) has given ‘stuff’ to another address (purchasers’ public key).

“You’re most likely familiar with stablecoins that hold USD in bank accounts and issue tokens on a blockchain that are ‘backed’ by these dollars. I call this legally-backed crypto, or an IOU coin, because if those bank accounts should ever be frozen or if the accountants defrauded token holders, the stablecoin now becomes an IOU on whatever’s left when they eventually get the bank accounts back (if they ever regain the bank accounts). Relying on the legal system to maintain crypto-tokens inserts an unreliable middle-man into the blockchain.”

Ethereum addresses are composed of the prefix "0x", a common identifier for hexadecimal, concatenated with the rightmost 20 bytes of the Keccak-256 hash (big endian) of the ECDSA public key. In hexadecimal, 2 digits represents a byte, meaning addresses contain 40 hexadecimal digits. One example is 0xb794F5eA0ba39494cE839613fffBA74279579268, the Poloniex ColdWallet. Contract addresses are in the same format, however they are determined by sender and creation transaction nonce.[55] User accounts are indistinguishable from contract accounts given only an address for each and no blockchain data. Any valid Keccak-256 hash put into the described format is valid, even if it does not correspond to an account with a private key or a contract. This is unlike Bitcoin, which uses base58check to ensure that addresses are properly typed.
In 2016 William Mougayar wrote a brilliant piece explaining blockchain technology by leveraging something we all know about: word processing programs. He reminds us that when Microsoft Word was the only game in town, one person had to create a file, open it, then send it to another person to have it edited or updated. The similarity to banks is striking, and makes it clear why blockchain technology was created in the first place:
Here’s why. Ethereum is based on blockchain technology where all transactions are meant to be irreversible and unchangeable. By executing a hard fork and rewriting the rules by which the blockchain executes, Ethereum set a dangerous precedent that goes against the very essence of blockchain. If the blockchain is changed every time a large enough amount of money is involved, or enough people get negatively impacted, the blockchain will lose its main value proposition – secure, anonymous, tamper proof & unchangeable.
Binance Update: Binance offers $250,000 reward for details that lead to arrest of hackers. The China-based cryptocurrency exchange began live trading in July 2017, so is fairly new to the crypto exchange world. However it has proven itself thus far to its clients, with its robust charting software and both basic and advanced interfaces attracting novice and expert traders. We've written an in depth analysis of Binance

The cool thing is that blockchain technology can be used for much more than financial transactions. It was designed to not have a single point of failure, and to be fully transparent. That's why you see it rapidly emerging in the gaming space, too. It can be utilized for secure cloud storage distributed across thousands of computers. Physical objects could conceivably be given unique digital ownership or identities. Anything of value can be integrated with blockchain technology. The possibilities at this point are endless and reliant on the imaginations of developers.


Good morning, traders. Binance completed the update to its platform overnight and Bitcoin price continues to feel pressure. With CBOE expiry later today, traders must remain vigilant if they are interested in trading this area as we could likely see price pop up at/near that time. However, we may see more movement down toward $6100 first. Notably, 1D OBV has ...
“You’re most likely familiar with stablecoins that hold USD in bank accounts and issue tokens on a blockchain that are ‘backed’ by these dollars. I call this legally-backed crypto, or an IOU coin, because if those bank accounts should ever be frozen or if the accountants defrauded token holders, the stablecoin now becomes an IOU on whatever’s left when they eventually get the bank accounts back (if they ever regain the bank accounts). Relying on the legal system to maintain crypto-tokens inserts an unreliable middle-man into the blockchain.”
Many litecoin investors followed the wrong herd last December when its founder Charlie Lee sold all of his shares in the company to avoid a conflict of interest. This should have indicated to investors that the price would not hold and would decline, Spatafora says. Instead of selling, many crypto investors bought more litecoin "like idiots when it was not sustainable," he says.

Coinbase is probably the easiest and safest way to purchase bitcoins in the U.S. Unlike BitStamp, Coinbase is not an exchange. They act as a counter-party to all customer trades, you buy or sell your bitcoins directly to Coinbase. The buy/sell fee is 1% on top of the buy/sell spread. The bid/ask is usually close to BitStamp where the firm gets its liquidity from. For example, the current bid is at $635.48 and the current ask is $638.07. In addition to this, the firm has daily limits on the amount of bitcoins bought/sold. These limits are not applied on the individual level. Basically Coinbase has a set amount of bitcoins that it is willing to buy or sell every day. During times or high volatility, users may not be able to buy/sell bitcoins until Coinbase decides to ‘’refill’’ their stock. Here’s a good explanation on this issue from their Customer Support:
Bitcoin solves the so called ‘’double spending problem’’ present with digital goods. For example, if I have an mp3 file or an ebook on my computer, I can freely copy that file a thousand times and send it to a thousand different people. For a digital currency, the possibility for unlimited copying would mean a quick hyperinflationary death. Bitcoin solves this by maintaining a peer to peer network and recording each transaction in a public ledger called the block chain. Say I send 1 bitcoin from my bitcoin address to my friend John. The bitcoin network records that transaction in the block chain and I no longer have possession of that bitcoin. The coin ‘’moved’’ from my bitcoin wallet to John’s wallet.
Bitcoin is the world’s first digital currency and it is expanding in popularity worldwide. Now, traders can trade Bitcoin with AvaTrade as the ideal asset in CFD trades. With our platform – MetaTrader 4 you can trade this rapidly growing currency against the US Dollar 24/7. Bitcoin is highly regarded among currency traders and its volatile nature makes them ideal for CFD trading.
The Ethereum network is kept running by computers all over the world. In order to reward the computational costs of both processing the contracts and securing the network, there is a reward that is given to the computer that was able to create the latest block on the chain. Every 15 seconds, on average, a new block is added to the blockchain with the latest transactions processed by the network and the computer that generated this block will be awarded 3 ether. Due to the nature of the algorithm for block generation, this process (generating a proof of work) is guaranteed to be random and rewards are given in proportion to the computational power of each machine.
Vitalik Buterin picked the name Ethereum after browsing Wikipedia articles about elements and science fiction, when he found the name, noting, "I immediately realized that I liked it better than all of the other alternatives that I had seen; I suppose it was the fact that sounded nice and it had the word 'ether', referring to the hypothetical invisible medium that permeates the universe and allows light to travel."[15]

One advice I’d give beginner traders is to avoid falling for ICOs, or Initial Coin Offerings, in the short term and stick with the more established currencies like Bitcoin, Eurotheum and Litecoin. According to MarketWatch, an ICO is “a fundraising means in which a company attracts investors looking for the next big crypto score by releasing its own digital currency in exchange.” The ICO is similar to a initial public offering (IPO), but with a crypto twist and (as of now) no regulatory hoops to jump through.
My question has always been where do you put your coins when selling? If I sell a token it automatically goes to Bitcoin … but you’re still exposed to crypto volatility. To sell that Bitcoin and transfer it back to my bank just doesn’t make sense. Is there a way to leave it as dollars somewhere? Also, is there offline storage for all the other misc tokens?

More important, Nakamoto built the system to make the blocks themselves more difficult to mine as more computer power flows into the network. That is, as more miners join, or as existing miners buy more servers, or as the servers themselves get faster, the bitcoin network automatically adjusts the solution criteria so that finding those passwords requires proportionately more random guesses, and thus more computing power. These adjustments occur every 10 to 14 days, and are programmed to ensure that bitcoin blocks are mined no faster than one roughly every 10 minutes. The presumed rationale is that by forcing miners to commit more computing power, Nakamoto was making miners more invested in the long-term survival of the network.
What separated these survivors from the quitters and the double-downers, Carlson concluded, was simply the price of electricity. Survivors either lived in or had moved to places like China or Iceland or Venezuela, where electricity was cheap enough for bitcoin to be profitable. Carlson knew that if he could find a place where the power wasn’t just cheap, but really cheap, he’d be able to mine bitcoin both profitably and on an industrial scale.
By October 2009, the world’s first Bitcoin exchange was established. At the time, $1 was the equivalent of 1,309 Bitcoin. Considering how expensive Bitcoin is today, that was a real steal. Bitcoin traded at a fraction of a penny for quite some time. Things started changing in 2010; as the distribution of Bitcoin increased, the digital currency became inherently more valuable.
Ethereum was initially described in a white paper by Vitalik Buterin,[16] a programmer involved with Bitcoin Magazine, in late 2013 with a goal of building decentralized applications.[17][18] Buterin had argued that Bitcoin needed a scripting language for application development. Failing to gain agreement, he proposed development of a new platform with a more general scripting language.[19]:88
The availability of options. Many options for trading cryptocurrencies on the exchanges serve as a benefit for the users. In particular, CEX.IO offers trading opportunities for Bitcoin, Bitcoin Cash, Bitcoin Gold, Ethereum, Zcash, Dash. They can be traded for USD, EUR, GBP, or RUB. Additionally, the variety of payment options, including cards like Visa and Mastercard, as well as wire transfers, contributes to the convenience of the service.
"People always think they are going to go in and buy when it's the dip," he says. "Say bitcoin is trading at $10,000, then a lot of selling occurs and causes panic and some investors reenter at $7,000. Then bitcoin bounces at $8,000, but goes back down to $6,000 and people buy back in thinking it's going back up and they are making money hand over fist."
A market order in this case would submit a buy order for XBT at the price of the lowest available sell order. Using the orderbook above, a market order for 0.5 XBT would purchase 0.5 XBT at $384.07 per XBT. If selling bitcoins, a market order would sell bitcoins for the highest available price based on the current buy orderbook—in this case $382.5.
The reward for doing so -- a miner's fee if you will -- is payment in that block's coin. The payment is based on how much their hardware contributed to solving that puzzle. Where do the coins come from? By design, that's exactly how the coins are created. The block is solved and coins and distributed fairly to miners. This increases the coin's supply.

Etoro.com is one of the latest forex brokers to offer bitcoin trading. Unfortunately, the product is not very suitable for day trading as you can only enter and exit the market four times per day. It uses the BitStamp’s data feed as a price reference. You can read more about Etoro’s bitcoin offer here.  Here’s a snapshot of their bitcoin CFD in action:
Look at where BTC is — right back in the apex of the triangle. You can see that it has fallen exactly to my rising black trendline, just as I had warned in several of my last BTC posts. Remember, I told you all that "if the buyers don't buy, the sellers WILL sell." BTC has been destroyed by the 50 EMA, so the sharks came in for some easy money. During the selling, ...
Cryptocurrencies aren't printed out like traditional money; they are mined out of a system. Cryptocurrency mining is simply the process of generating new units of cryptocurrency. Mining systems, which are a vast pool of computers running a mining program for a certain cryptocurrency, verify transactions on the blockchain and add these records to a public ledger. In essence, mining provides bookkeeping services to the coin network.
Ether is a fundamental cryptocurrency for operation of Ethereum, which thereby provides a public distributed ledger for transactions. It is used to pay for gas, a unit of computation used in transactions and other state transitions. Mistakenly, this currency is also referred to as Ethereum.[48] It is listed under the code ETH and traded on cryptocurrency exchanges, and the Greek uppercase Xi character (Ξ) is generally used for its currency symbol. It is also used to pay for transaction fees and computational services on the Ethereum network.[49]
Cryptocurrency mining is a way to get Bitcoins. Of course, it is possible to buy them, but Bitcoin mining creates new ones by making new parts of the blockchain. In defining cryptocurrency mining, it should be stated how it actually works. In order to mine, there must be a peer-to-peer computers network so that tasks can be performed with their combined computing power. The more computers and less centralized the system, the faster tasks will be operated. Each computer is called a host in the blockchain and the network works based on a cryptographic protocol. By recording and confirming new operations into a virtual, replicated, and distributed public database known as the blockchain, miners (those who do mining) create new parts of the chain and they receive 12.5 Bitcoins for each new part as a reward. The new block can be made just once in 10 minutes so that to synchronize all operations, assure they are mathematically accurate and be able to spread it around all users.
Ethereum enables developers to build and deploy decentralized applications. A decentralized application or Dapp serve some particular purpose to its users. Bitcoin, for example, is a Dapp that provides its users with a peer to peer electronic cash system that enables online Bitcoin payments. Because decentralized applications are made up of code that runs on a blockchain network, they are not controlled by any individual or central entity.
×