Test tx of 0.1 before sending.

https://www.blockchain.com/btc/tx/9895f1e94d0df7fd04e1289f34...

I usually test with 0.00001

Ah yes, just a cool $1,000 test

That transaction cost 0.00530724 BTC or 55$. Why is it different than the final one?

The final transaction is a total of 13611 bytes in size while the test one is 1220 bytes. There is a fee per byte in the Bitcoin UTXO model. An unspent transaction output (UTXO) contains information about who can spend the bitcoin so there is a fee attached to every byte of information in a UTXO because miners spend computing power processing every byte. The final transaction contained 15 UXTOs which made it a lot larger in size than the test one which only contained 4 UTXOs. The final transaction had a fee of 480 satoshis per byte and the test one had a fee of 435 satoshis per byte.

13611 * 480 = 6533280 sats which is 0.06533280 BTC which is ~$675 USD

1220 * 435 = 530700 sats which is 0.00530700 BTC which is ~$55 USD

if you're wondering why the fee per byte is not the same for both transactions, it's probably because the recommended fee fluctuates depending on network congestion throughout the day. If you're wondering why the transaction fee per byte is higher than average, well it's probably because the sender is a billionaire who doesn't really care and just wants their transaction processed quickly.

You don't have to be a billionaire to want your btc transaction processed quickly.

Well yes obviously it doesn't matter but that fee is way higher than average for a fast transaction meaning they're ok with spending a lot more than the average sender.

You could, but you'd also have to modify the checksum built into the bitcoin addresses in order for most (all?) bitcoin clients to broadcast the transaction.[1][2]

[1] https://en.bitcoin.it/wiki/Address

[2] https://en.bitcoin.it/wiki/Technical_background_of_version_1...

It looks like they sent 0.1 BTC as a test before sending the big transaction.

"Life changing amount of money" is an understatement. Imagine trying to launder a billion dollars, surreptitiously.

I've done this for~$500 in ETH, but I received that as payment for code written months ago that never passed review, so I wasn't expecting it anyway. Still a bit of an emotional roller-coaster to receive free money, then inadvertently throw it away within a few minutes.

Yeah. It seems silly to perform this transaction all at once. The size of this transaction magnifies the consequences of any sort of error and attracts what I'm guessing is very unwanted attention.

If you’re a whale and want to someday liquidate this, ideally at higher value, you want the world to see big things like this. It will remind people that bitcoin network is still very much alive despite the repeated death sentences made by supposed financial experts.

Well, on the other hand you can also look at this and think, I better not put any money into bitcoin, cause there are individuals out there that could single-handedly destroy the price by cashing out. And you might say, it is in their interest not to do that, but I think it is in their interest to be the the first one to do that.

Nah, the smarter plan is to keep the dream of bitcoin alive while you trade your bitcoin for other assets; this is how companies buy other companies with stock-only purchases.

In which case it’s extremely unlikely that you would name another valid address; so your transaction would eventually be invalidated.

Correct me if I'm wrong, but afaik there is no "eventual" invalidation in bitcoin: either the destination address fails the checksum (so nodes immediately reject the transaction), or you send the funds to an (unused) address where they'll sit forever.

You are mostly correct. Except only your Bitcoin client sees the checksum/address, the raw transaction has just the pubkey hash encoded in the address. So there is no checksum for other nodes to check. If you accidentally crafted a transaction with the wrong hash in the scriptPubKey, the network would happily accept it.

If the transaction doesn’t end up in the canonical version of the blockchain (ie the nlockchain still says its unspent), then surely you can transfer it again, no?

Of course if the blockchain does say it was transferred to a nonexistant address then its gone forever. I guess if it passes checksum, this is the likely scenario?

A tx will go from your client (which should reject an invalid tx to start with) to a node (which will verify and reject an invalid tx) to many other nodes (which will all verify and reject an invalid tx) to the node that's publishing the next block (which will verify and reject an invalid tx). I guess a broken client could think a tx is valid when it's not and not let you re-spend it, but it'll be rejected pretty much immediately after that.

Technically there is no such thing as a nonexistent address. There are used and unused addresses -- an unused address is just an address with no history, but there's no way to tell if anyone has the private keys for it or not. I guess it's possible accidentally typo an address that somehow passes checksum (let's pretend that people actually type in addresses... nobody does that, copy/paste or QR code) but it's very very unlikely.

For the checksum tech details: https://en.bitcoin.it/wiki/Base58Check_encoding#Creating_a_B...