Kraken works well through SEPA, has an easy verification process (expect 4-6 weeks vetting with current backlog) compared to Bitstamp, and is very knowledgeable when it come to cryptography and security. As of early 2017, this platform has been re-positioning themselves as a crypto exchange by adding multiple new altcoins. I've written an in-depth Kraken review with everything you need to know..

No Transaction Costs: All bitcoin transactions are digitally recorded on public networks without any involvement from banks or clearing agencies. Hence, there are usually no transaction costs involved in bitcoin, even for global transfers. Brokers pass these benefits to the clients by not imposing any deposit or withdrawal fee for bitcoin transactions. This improves trade profits.

During the launch period, members may enjoy reduced fees of $1 per contract to enter a trade and another $1 to exit at or before expiration. However, Nadex will waive your settlement (exit) fee if the market settles below the floor price (for long positions), or above the ceiling price (for short positions). Thus, your maximum possible fees would be $2 a round-turn per contract. After the launch period, the fees will be $2 per contract on entry and another $2 to exit at or before expiration. Nadex will still waive the settlement fee for trades which incur the maximum potential loss.
The overwhelming majority of bitcoin transactions take place on a cryptocurrency exchange, rather than being used in transactions with merchants.[134] Delays processing payments through the blockchain of about ten minutes make bitcoin use very difficult in a retail setting. Prices are not usually quoted in units of bitcoin and many trades involve one, or sometimes two, conversions into conventional currencies.[31] Merchants that do accept bitcoin payments may use payment service providers to perform the conversions.[135]
The level of security among pools also varies greatly, from simply requiring a BTC username to requiring a 2-Step Google Authenticator code before paying out. Luckily, given the anonymous nature of Bitcoin, you generally won't have to include any personable, stealable, information. Still, money and complete strangers can be a particularly combustible situation.
Bitcoin paints a future that is drastically different from the fiat-based world today. This is either exciting or unsettling for the vast majority. Equip yourself with the best possible resources. Become active in communities that further explore not only the technical applications of Bitcoin and other cryptos, but with their overall potential to disrupt virtually every market. Brace yourselves. Cryptos are coming.
The overwhelming majority of bitcoin transactions take place on a cryptocurrency exchange, rather than being used in transactions with merchants.[134] Delays processing payments through the blockchain of about ten minutes make bitcoin use very difficult in a retail setting. Prices are not usually quoted in units of bitcoin and many trades involve one, or sometimes two, conversions into conventional currencies.[31] Merchants that do accept bitcoin payments may use payment service providers to perform the conversions.[135]
Many people believe that cryptocurrencies are the hottest investment opportunity currently available. Indeed, there are many stories of people becoming millionaires through their Bitcoin investments. Bitcoin is the most recognizable digital currency to date, and just last year one BTC was valued at $800. In November 2017, the price of one Bitcoin exceeded $7,000.
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[92] and links it to Tulip mania.[93] American business magnate Warren Buffett thinks that cryptocurrency will come to a bad ending.[94] In October 2017, BlackRock CEO Laurence D. Fink called bitcoin an 'index of money laundering'.[95] "Bitcoin just shows you how much demand for money laundering there is in the world," he said.
As of November 2017, Bitcoin and other digital currencies are outlawed only in Bangladesh, Bolivia, Ecuador, Kyrgyzstan and Vietnam, with China and Russia being on the verge of banning them as well. Other jurisdictions, however, do not make the usage of cryptocurrencies illegal as of yet, but the laws and regulations can vary drastically depending on the country.
Peercoin is another cryptocurrency which uses SHA-256d as its hash algorithm. Created around 2012, this cryptocurrency is one of the first to use both proof-of-work and proof-of-stake systems. The inventor of Peercoin, known as Sunny King, saw a flaw in the proof-of-work system because the rewards for mining are designed to decline over time. This reduction in rewards increases the risk of creating a monopoly when fewer miners are incentivized to continue mining or start mining, thus making the network vulnerable to a 51% share attack. The proof-of-stake system generates new coin depending on the existing wealth of each user, so if you control 1% of the Peercoin currency, each proof-of-stake block will generate an additional 1% of all proof-of-stake blocks. Incorporating a POS system makes it significantly more expensive to try and attain a monopoly over the currency.
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:
“In 2 years from now, I believe cryptocurrencies will be gaining legitimacy as a protocol for business transactions, micropayments, and overtaking Western Union as the preferred remittance tool. Regarding business transactions – you’ll see two paths: There will be financial businesses which use it for it’s no fee, nearly-instant ability to move any amount of money around, and there will be those that utilize it for its blockchain technology. Blockchain technology provides the largest benefit with trustless auditing, single source of truth, smart contracts, and color coins.”

It's fascinating that @jimmysong talks anti-fragility but only sees BCH as an attack rather than an anti-fragility response to SegWit. Maybe someday he'll realize having BCH makes bitcoin stronger -- the hydra dies only after cutting off *all* heads: …

It should also be noted that the timestamps on the subsequent blocks indicate that Nakamoto did not mine the first blocks in an attempt to keep them for himself and make profit this way. Yes, Nakamoto was awarded Bitcoins as he was the first and a sole miner for some time, but this continued only for about 10 days after the launch of the Bitcoin network. The only thing that Nakamoto used his Bitcoins for was a few test transactions. Starting from around mid-January of 2009, those Bitcoins were left unspent. Anyone can check the public log of Nakamoto’s Bitcoin address, which shows roughly 1 million Bitcoins. This amount of Bitcoins is roughly equal to about $2.8 billion USD. Needless to say, Nakamoto’s invention was a success.
The debate over whether bitcoin should be considered a legal tender has accelerated in the wake of the high-profile attack of Japanese exchange Mt. Gox and the widespread adoption of it in payment processing at major U.S. retailers. Unlike the U.S. dollar, the Chinese yuan, or the euro, bitcoin is not recognized universally as a currency by every participant of the global markets, including regulators and government officials.
Though karma rules still apply, moderation is less stringent on this thread than on the rest of the sub. Therefore, consider all information posted here with several liberal heaps of salt, and always cross check any information you may read on this thread with known sources. Any trade information posted in this open thread may be highly misleading, and could be an attempt to manipulate new readers by known "pump and dump (PnD) groups" for their own profit. BEWARE of such practices and excercise utmost caution before acting on any trade tip mentioned here.
Transactions that occur through the use and exchange of these altcoins are independent from formal banking systems, and therefore can make tax evasion simpler for individuals. Since charting taxable income is based upon what a recipient reports to the revenue service, it becomes extremely difficult to account for transactions made using existing cryptocurrencies, a mode of exchange that is complex and difficult to track.[66]
The father of Bitcoin was able to not only code an exceptionally well built system, but also found clever ways to ensure his work was validated and not misunderstood for some sort of a scheme by others. For example, Nakamoto left a message inside this first manually altered code. When the first block of Bitcoin was mined, it read ‘The Times 03/Jan/2009 Chancellor on brink of second bailout for banks.’ This quote is the headline for The Times newspaper which was published on January 3rd, 2009. The clever use of this simple message is overlooked by many, and it dictates that the first block was mined no earlier than January 3rd, 2009. This is extremely important because the whole Bitcoin system is designed to run and validate itself from the previously mined blocks, so giving a valid timestamp which can be authenticated by a simple headline title to the first block was genius. Afterwards, all blocks used the previous block for reference.
To heighten financial privacy, a new bitcoin address can be generated for each transaction.[114] For example, hierarchical deterministic wallets generate pseudorandom "rolling addresses" for every transaction from a single seed, while only requiring a single passphrase to be remembered to recover all corresponding private keys.[115] Researchers at Stanford and Concordia universities have also shown that bitcoin exchanges and other entities can prove assets, liabilities, and solvency without revealing their addresses using zero-knowledge proofs.[116] "Bulletproofs," a version of Confidential Transactions proposed by Greg Maxwell, have been tested by Professor Dan Boneh of Stanford.[117] Other solutions such Merkelized Abstract Syntax Trees (MAST), pay-to-script-hash (P2SH) with MERKLE-BRANCH-VERIFY, and "Tail Call Execution Semantics", have also been proposed to support private smart contracts.
An increase in cryptocurrency mining increased the demand of graphics cards (GPU) in 2017.[37] 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.[38] 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.[39]
It's like when Steve Jobs saw Steve Wozniak and his gang of nerds building computers. He instantly recognized the power and importance of the personal computer, but also instantly recognized non-enthusiasts would never want to solder circuits together in their garage. Love Apple or hate it, together the Steves made personal computing accessible for the masses. What crypto is doing right now is precisely the opposite, making it even more arcane, even more silly with petty feuds and slapfights over what so-and-so's "vision" was. The average Joe is going to see this, have no idea how to get involved nor want to, and is instead going to pay for whatever with ApplePay or good old fiat.
Isn’t there something out there in place to protect my potentially fake investment? Truth be told, you are sort of out of luck. You see, most of these ICO coin tokens are designed in a way that marks them as ‘software presale tokens.’ So essentially, your ICO coins are no different than a video game token that you bought before it launched. The main reason many developers choose to address their new currency in such a way is to avoid paying all the expenses that come alongside legal sales. In a similar matter, a developer of a newfound cryptocurrency might choose to say that his or her investors are ‘donating’ coins to their cause and what not. So while this is completely acceptable and falls under the same reasoning for why Bitcoin was invented in the first place, to decentralize and stop all the crazy fees that go into making these investments happen, it’s still relatively questionable.
Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network.[3]:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.[81]