You should definitely avoid keeping them on an exchange. A few years is a lifetime in the cryptocurrency space, and your exchange could easily be hacked and shut down during that time. Plus, trusting a third party to take custody of your BTC sort of defeats the purpose of Bitcoin, which is intended to allow you to "be your own bank."

The easiest solution for a newbie is just to buy a hardware wallet like a TREZOR or Ledger Nano S. I would suggest only buying directly from the manufacturer:
https://trezor.io/
https://www.ledgerwallet.com/

Personally, I keep my long term cold storage on an air-gapped PC. But this method of cold storage is becoming obsolete now that hardware wallets are becoming the norm.

As far as web wallets go, I would say that Greenaddress is safe, yes. They are owned by Blockstream and have a very good reputation. I've used them in the past and never had any problems. It should be noted that they use 2-of-2 multisig addresses, which create larger transactions and therefore have higher fees. This has been somewhat mitigated since they implemented Segwit.

Your default receiving address will change after you have received a BTC payment. Other services usually do the same.


Not exactly. Private keys correspond to key pairs. So, each Bitcoin address has a corresponding private key. Your mnemonic is a "seed" that gives access to all the private keys in your wallet.

Note: Unless things have recently changed, your money is stored in 2-of-2 multisig addresses. Your seed provides one of the keys. In case you need to recover your wallet, Greenaddress uses the 2nd key to pre-sign an nlocktime transaction that spends the money back to an address under your control after a certain time. See more here: https://greenaddress.it/faq/

I have mixed feelings. On one hand, I don't appreciate it as a trader. I literally have been seeing notifications throughout the day about my orders being cancelled. One the other hand, these are fairly standard measures that one would expect any institutional-level exchange to implement if they want to be a serious contender in a regulated market. With all the recent changes (included stiffer KYC), it looks like that's the direction that Bittrex is heading. The note about pump groups is indicative.

At this point, I'd definitely advise people to withdraw funds from the site if your ID documents aren't going to match the personal info you gave them. These are all signs of an exchange that's trying to "go clean."

Is it surprising that this was their first reaction? Indeed, a few years ago, Russia's Prosecutor General said that BTC payments were illegal. And US Congresspeople were also calling for it to be banned. But look at how far we've come..... now Vitalik Buterin is meeting with Vladimir Putin, and a local Russian governor invited miners to set up farms in his province. And the US market is now getting regulated futures products from LedgerX and the CME group.

I heard once that Bitcoin needs to be banned in a few places for it to remain relevant. I guess it means that governments can see that it's gaining a foothold among their citizens. In the end, governments can't stop it. They can't stop P2P transactions, no matter how much surveillance and packet analysis they do. Recently, Vietnam and Morocco have banned the use of BTC. It looks like BTC is still relevant!

Absolutely. There are rumors circulating that the Russian Federation will create a "Crypto-Ruble" that will essentially be a centralized blockchain backed by fiat money. I imagine they want to capitalize on the Bitcoin/blockchain hype, but push citizens towards regulated/surveilled payment systems. There are also similar rumors in China. The Bank of China has already developed and released an app called "Blockchain e-wallet" in the App Store. Supposedly it will be linkable to BOC debit cards. There is no functionality included for Bitcoin and other cryptocurrencies.

So I definitely think we are entering a new era of state-backed "cryptocurrencies" as governments try to steer their citizens away from decentralized money. As far as legalization, I think the cat is out of the bag. It's too late for major powers to effectively make Bitcoin illegal. That would work out like historic gold bans -- failures.

How can you "refuse to allow" anything? Anybody is allowed to fork an open source software. If the community is not interested in the fork, they don't need to use it -- simple as that. Unfortunately, the exchanges don't want to miss out on trading commissions, so they'll list anything that will make them money.

The fact is: It's a free market. Exchanges are free to list whatever coins they want. Investors can buy/sell whatever coins they want. Eventually, people will grow tired of these shenanigans and will start to understand that these forks are just cash grabs. And then money will flow back into cryptocurrencies with strong fundamentals, like Bitcoin. Newbie investors who wanted to get in on "the next Bitcoin" are going to get fleeced and lose a lot of money.


Because the Bitcoin Diamond "developers" want to make some money. And so do exchanges, so they will list it. The funny thing is, I felt like the altcoin market was diluted when there were 200-300 coins. Now there's 1300 and counting. And money still just keeps flowing into the market!

My grades for the exchanges, along with my reasoning, is below:

Bittrex - C: Recent scare around locked/disabled accounts, lots of recent KYC/security changes, service has also degraded in recent months.
Coinbase/GDAX - A: Licensed and FDIC-insured. I'm comfortable leaving funds here. Free limit orders on GDAX. Not the best trade engine in the world, though.
Kraken - D: Terrible trade engine, does not answer for it and service seems only to degrade more over time.
QuadrigaQC - N/A: not familiar with this exchange.
CoinCorner - N/A: not familiar with this exchange.
Poloniex - C: Long support waits, lots of glitches; I don't keep funds here for long.
CanadianBitcoins - N/A: not familiar with this exchange.
BitFinex - D: Hacked, involved in unregistered securities/derivatives, unlicensed.
BitHumb - D: Seems to be involved in lots of pumping/manipulation, went down for 12 hours at top of BCH pump.
BitStamp - A: One of the most reliable, longstanding exchanges. Licensed. I'm comfortable leaving funds here.

I haven't dealt with this myself. I had a friend who lost access to their 2FA on BTC-e and they allowed him to log in after freezing the account for ~2 weeks, since he had his login, control of his email address, and could provide ID/selfie. I'm guessing there is a similar recovery protocol at Bitfinex...... I would hope that they would freeze withdrawals for a period of time in case there was a dispute over account ownership.

This is an important lesson: Always make multiple backups of your 2FA secret when you generate it. I put one on my main phone, one on an old phone that never leaves my house. I also write the code down on paper in case both devices fail.

The problem is that it's easy for even one person to generate those sock puppets and then claim that all the complaints are fake. I've definitely seen several accounts from people that didn't appear fake, including some that had their accounts re-enabled. Bittrex also released a statement which stated that  < 0.1% of accounts were affected. Both of these things suggest to me that the account locking debacle is real.

So, how much does 0.1% of accounts really represent? I've had multiple Bittrex accounts over the years, all of which are empty now. Are they including my empty accounts in their calculation? Because everyone who complains about having their account disabled had money in their account. IMO, more people are/were probably affected than the exchange suggested.

It's not useful to think of "the miners" as this single, monolithic entity. Miners are competing with one another for those fees. Bitmain might control a lot of hash power, but they don't have a monopoly on it. It's not like a supermarket chain can singlehandedly drive up the prices of milk just by marking it up in their stores.

Mining pools are all trying to undercut one another with hash power distribution and better mining/propagation code, and as subsidy drops, the incentive is increasingly about fees. What you're saying can only be true if all miners are colluding together to keep fees high. That seems unlikely given global distribution and competition, but I'm interested in hearing any evidence you might have.

I'm not surprised. That was expected, given the magnitude of the FUD (hit pieces from the New York Times)... but just like the bank run subsided after the hack last year, I think this will too. I think they'll bounce back because they just got USD banking back online, and now have EUR deposits/withdrawals.

Kraken is also having lots of performance issues these days, and they are the BTCEUR leader. Bitfinex just added BTCEUR to compete with them. I'm curious to see how that turns out. Personally, I dislike both exchanges, but I'm really at my wit's end with Kraken....

It's an active attack that appears to go back to at least 2017-11-09. I think it's a bit premature to assume that Blockchain.info is compromised based on this information alone. A handful of "unauthorized transaction from my wallet" posts usually suggests a phishing scam of sorts.

I've seen multiple reports of a scam targeting Blockchain.info users. It goes like this: "Check out this profit-generating mining scheme. Set up a BCI wallet, give me your username/password while it's empty, I'll set up the wallet for mining generation, then you change your password." The attacker drains any future funds via the HD recovery seed. It's crazy that people would fall for such an obvious scam, but there are a lot of suckers out there.

So yeah, I'm guessing it's a phishing scam targeting Blockchain.info users, not a compromise of the service itself. If they were compromised, the attackers would have made off with much more than 26.52202749 BTC.

Coinbase is great for fast ACH transfers, if you use them to sell BTC. Make sure to use their exchange interface (GDAX) so you can take advantage of their no-fee limit orders.

However, I wouldn't use them for a wallet. Like any third party service, I would only risk keeping coins there for a limited time, e.g. waiting for asks to get filled and withdrawing USD to my bank account.

I highly recommend Electrum for a convenient light client. But if you are talking about mining, then you'll need to be running a full node.

Tether appeared to be fairly legitimate as of a year ago. Lots of people used it to arbitrage the markets, they had a standard KYC process and standard bank wire service.

It wasn't until March of this year -- when both Bitfinex and Tether lost banking capabilities -- that things started to get really fishy. For one thing, did they "lose banking capabilities" or are they insolvent? We'll never know, and while Friedman LLP has apparently looked at Tether's books, their statements don't confirm that Tether has access to funds backing all USDT in circulation.

The "theft transaction" narrative seems unnecessary, since nobody can withdraw USD from Tether (or Bitfinex), and they haven't been able to for many months now. Then again, who would be dumb enough to bother hacking Tether? It's centralized; they can just freeze your funds and/or fork the network.

Same here. BTC-e was always the most reliable exchange in a sea of unreliable APIs and broken trade engines. I used it since 2012 and I miss it a lot. Even though I lost a lot taking the 55% refund option, I'm sometimes tempted to come back to WEX.

But I'm still upset that they waited until the very last moment to say that verification would not be required to trade on the new platform (WEX). They were vaguely threatening KYC requirements for days until I finally said "screw it" and took the refund. I couldn't risk KYC as a US customer.


Here's what I don't understand: When WEX launched, they said that all previous verification data had been "destroyed." Why is there a name associated with your account? Was it carried over from BTC-e or did you provide it in an attempt to verify?

Currently, based on the consensus rules, the supply is unlimited. The circulating supply is ~95,870,000 ETH. The current block reward is 3 ETH. After Byzantium, block time is ~ 15 seconds, so that amounts to 12 ETH generated every minute.

At some point, Vitalik Buterin said he was aiming for a total supply ~ 100 million ETH before transitioning to proof-of-stake. But that was some time ago, and I think he and many others underestimated the daunting work of building a POS system at Ethereum's scale.

I recall that he also floated the idea of perpetual low (1-2%) inflation, for security, which I don't think is entirely unreasonable. The premises underlying Bitcoin's post-subsidy security are untested too. We'll see what works best in the end...

Why? BTC has been outperforming most of the markets, with a few short-lived pumps aside. The BTG/USD chart actually looks fairly bullish to me, like it's emerging upwards from an accumulation phase. So you might get your wish.


I don't think Bitfinex deposits/withdrawals are active yet for Bitcoin Gold. 5 days ago, their support team said:


So it looks like anyone with BTG on Bitfinex is still stuck. Deposits/withdrawals are active on HitBTC and Bittrex. Bittrex also just opened a new BTG/USDT market a few hours ago.

The keys in question were compromised. Bitstamp was hacked in January 2015. On the 5th, it was reported that they lost 19,000 BTC in a compromise of their hot wallet.

Accordingly, they could not honor or credit any bitcoins sent to old deposit addresses after the compromise was discovered and publicly announced. Any bitcoins sent to these addresses are probably immediately swept by the hackers via script.

It sucks for the OP, but it's incumbent upon customers to check their deposit address every time they make a new deposit. People can't just endlessly send coins to compromised wallets and expect Bitstamp to cover the losses out of pocket. They already covered 19,000 BTC out of their own pockets back in 2015 over this.

Why would you send coins to a deposit address generated almost 3 years ago, without checking your Bitstamp deposit addresses first?

Color me skeptical! Wasn't this the same analysis that Vitalik Buterin was promoting in 2013, before formulating Ethereum? Here's a talk he gave back then outlining the supposed risks that quantum computing posed.

According to Gregory Maxwell, Vitalik even collected investments to fund the production of a "quantum" computer program intended to break Bitcoin. I'm pretty sure he shied away from the whole scheme. I'd love to see more research into this, but the brief isn't any more compelling now than it was four years ago.

In any case, I'm not too concerned about the threat of quantum computing. If the risk comes to fruition, it would be a fundamental protocol failure. Thus, the entire user base would be incentivized to hard fork to fix the vulnerability.

Functionally, that is no different than the current system of fiat money. That's the whole point of the proposed "Crypto-Ruble" (Russia) and "Crypto-Yuan" (China). They might be moving tokens onto a "blockchain," but it's still the same dirty old fiat money, with no limit on money printing. They are trying to trick people into thinking this economic transformation is about "blockchain technology" when it is really about financial sovereignty and decentralized money.


That's my view. Governments would need to be completely abolished for fiat money to disappear. Governments can simply require debts and taxes to be paid in fiat money, forcing you to trade/sell assets for it.