Look for addresses with > 1000 BTC that haven't been active in a while (several years). Those addresses are likely to be individually owned. Company owned addresses usually have coins flowing in and out.

The Oracle of Omaha has already stated that he does not understand Bitcoin and does not believe in it. It is unlikely that he would buy add bitcoins to his portfolio. He also invests his money wisely and conservatively so it would be out of character for him, for example, to buy 51% of coins just to destroy the system.

Nothing is really free. The banks' networks and computers cost money to operate and someone somewhere is paying for it and the costs will eventually be passed back to you in one form or another.

You realize that mining difficulty will adjust downwards if many miners stopped mining, resulting in the remaining miners starting to profit again.

Even when there are no more block rewards there will always be mining as long as users keep making transactions with non-zero transaction fees.

Lol, I am over 45 and still mining bitcoins. I got into BTC because my real job involves cryptography and financial software. I first learned about it 6 years ago while browsing through some crypto forums doing work related research.

This is not really a good excuse not to support Bitcoin transactions. Amazon always had the option of refunding payments to your giftcard balance and not necessarily always to the source of payment. In fact, refunding to your giftcard balance is instantaneous but to your credit card could take days.

Also with 3rd party sellers I would assume that they will receive the payment in fiat regardless of whether they buyer uses BTC or other forms of payment.

500 bitcoins is worth around $325K. I would find buyers who can wire you the money straight to your bank account. Unless you live in a banana republic, nobody is really going to ask questions about $325K worth of incoming wires into your account. If there are any questions that are asked, it is usually the sending bank that asks the sender of the wire (the buyer), not you.

On the other hand making cash deposits worth $325K could get your bank account randomly seized by the IRS in the US.

It takes one loose connector. Current initially flows through the other two until they burn out and their resistance increases above that of the first loose connector. Then the loose connector starts taking the load and it quickly burns out too. It happened to me more than once with Bitfury gear.

I don't usually publicize my addresses. If someone sent me coins to one of my addresses and I wasn't expecting it, it means they were snooping the blockchain and my addresse(s) in particular. I would be super pissed off and probably keep the coins just to teach them a lesson for snooping.

However, I would make some effort to figure out that it was not sent truly by accident and not because of snooping (copy pasting my addresses). If this were the case I would return the coins.

I'm curious, which Bitcoin exchanges are capable of supporting "high frequency trading"?

Most of my Genesis contracts became worthless after mining (in fiat) about 20-35% of their cost. In BTC the return was even worse. I'd like to know what period you purchased them. Mine were in early 2014.

I have a lot of cash parked in my IRA and would like to move some of that into BTC. I don't think you can buy real bitcoins directly from an IRA (at least without setting up some kind of complex trust), which is why the ETF would be real nice.

Hmmm  ... I just made a new private key in my mind? When will it be on the list? Before or after I write it down on paper?

21 BTC is about the price of a 3 year old used Toyota Corolla in the US. Unless you are still a student or you come from a third world country, it is still not too hard to buy 21 BTC using fiat.

Will the cops bother you if you use these lowers in a public shooting range? I understand it is legal to make your firearms as long as you don't sell them, but I've always wondered what the practical issues are related to possessing a gun with no serial number.

I have some miners in a DC full of nosey people. I prefer them to look like servers and I tape up the Spondoolies logo. Also the rats nest of 12V cables always attract attention from the fire safety people.

Edit: actually the most important thing for me is that the SP form factor is compatible with high-density racks because when installed properly with blocking panels the cold air does not leak around the sides of the miners but goes straight through them and sucked up into ceiling.

I do like the SP3x form factor and I still have a few running. Practically speaking nobody is going to bother making boards with 16nm chips for these miners. However, I've wondered about repackaging a couple of S9 miners into an SP3x shell using the dual power supplies. It would make a really nice 25 TH/s package.

I started mining seriously since early 2011 and 20% of the coins I've mined have gone to savings. Although I blown through the remaining 80% (mining equipment, speculation, bad investments, scams, cash out to fiat, etc.) , some of the coins in my savings addresses are over  5 years old. I was lucky in that I went through 2 phases of highly profitable mining - 1) early GPU mining, and 2) batch 1 Avalon ASICs.

This is not how elliptical curve cryptography works. Knowing one private key does not make it practically easier to find another private key that collides to the same public key.

Of course people have lost bitcoins. In 2010 I threw out a server with a wallet.dat file containing 100 BTC that were CPU-mined while I was playing around with an early client. To those who weren't around back then the Bitcoin core client mined/generated coins by default in pristine 50 BTC blocks straight into your wallet.dat. I had installed a node on an old 8-core server just to play around before the server was decommissioned a few days later. I noticed it had mined the 2 blocks before shutting it downed for the last time and sending the drives off to be DoD3 wiped.

It was only the next year when I got serious with BTC and realized how much value I had thrown out.