First of all exchanges don't really own those bitcoins. The balance belongs to users who have deposited their bitcoins on exchanges for trading and the exchange can't just sell those coins themselves!
Even if they do open orders on their own platform to sell those bitcoins for shitcoins, there still has to be other traders who have signed up on their platform to buy bitcoin with their shitcoins (aka dump their shitcoin) and then withdraw those bitcoins which is the same thing as people dumping shitcoins and withdrawing bitcoin as ever!

I think you may be confusing BIP-38 (Passphrase-protected private key) with BIP-39 (Mnemonic code for generating deterministic keys). The former is supported by only a handful of wallets and tools while the later is supported by almost everything. OP was talking about the former.

There has to be a massive manipulation, even bigger than first time to be able to bring the price below $45k at this point. In other words I firmly believe that it was the last time we saw anything smaller than $45k.
But even if we consider the possibility of something like that, the recovery won't be fast. Keep in mind that dropping to $35k is not a simple drop, it is a huge crash and market doesn't just recover from a crash.

It is easy to find the right order of the words specially if the word count is small, for example the most used word count which is a 12 word mnemonic, the permutations to check is 12!=479,001,600 and it is trivial to check those in less than half an hour in slowest way on a CPU, while a parallel GPU rig solves this in a couple of seconds.

This is exactly why you should never "invent" your own cryptography.

Everyone must double and triple check everything in their wallet's Send window before they actually sign the transaction and broadcast the transaction to the network. This is regardless of the method they are using. That is why I disagree with using this as a reason for not using this method since any other method (copy and pasting, or using QR) can have similar vulnerabilities that lead to a modified variables.

No, it is not.

The thing is that wallets are always HD so there is little use for a single key encryption technique for them. However the method itself is still useful and will remain useful for paper wallet creation.

Which is more than enough for a developer to implement it.

You are just not searching well enough:
A python bitcoin library:
https://github.com/1200wd/bitcoinlib/blob/c52cdfc9fe7feaedcf4dc3e43ceca4071865281b/bitcoinlib/encoding.py#L772-L845

A shitcoin wallet's library:
https://github.com/joshmcintyre/blockchainmower/blob/7457c361b5b2792e7cd3c4882713d6b71efddcda/src/electron_cash_lib/bitcoin.py#L1023

From a paper wallet builder:
https://github.com/ryanralph/DIY-Piper/blob/0df360f61707739dd7ba5b7758f79b7c8e136867/bitcoin/bip38.py#L17

A set of utilities from @darosior:
https://github.com/darosior/bitcoineasy/blob/master/bitcoineasy/bip38.py

Another paper wallet builder:
https://github.com/zobin8/PyperWallet/blob/master/pyperlib/cryptor.py

P.S. Note that I'm not endorsing any of the above links, just pointing out examples of python (mostly v3) implementation of BIP38. Aside from that there are lots of python 2 implementations that could simply be converted to python 3.

The major reason for it is not the past experience people had on the internet, it is mainly about the FUD that is being spread about bitcoin. Imagine for almost a decade you've been hearing a lot of negative lies about something, the only logical way to think about that thing would be negative! That is until something negates that FUD. Usually big adoption news does that, news such as a big company starting to accept bitcoin. Or the recent news about a couple of countries adopting bitcoin as legal tender.

I'm not comparing anything I'm just showing the trend and those prices are reported by the time of halving. Feel free to use any average price you like to see the same exact trend.

Also if you read my following line after the dates and prices I say that this is a trend that we had so far and there is no reason for it to change in the foreseeable future which is the next decade or two at least. What we can't predict is what will things be like after 100 years, saying anything about it is meaningless in my opinion.

If you sent that transaction from your Electrum wallet that means your wallet is either not-encrypted or you have the encryption password. In which case you should simply click on the seed icon at the bottom right corner of the Electrum window or from menu select Wallet > Seed to get your seed phrase.

As for canceling, you can not cancel a transaction when it is broadcast and nodes accepted it as valid. It can remain valid until the end of the world in different node's mempool until it either becomes invalid (double spent) or confirmed.
What you should do (if you don't want it to ever reach the current destination) is to double spend these coins. If the transaction was marked as RBF (default behavior on Electrum) your work should be simpler.
I'll let someone else explain the steps since I believe the new version added a "cancel" button and I haven't tested it. My alternative method would be complicated.

You are confusing the "reference implementation of Bitcoin" with "reference implementation of BIPs" they are not the same, ergo the BIPs reference implementation doesn't have to be in C++. In fact it should be in a langauge that the author of the BIP is most familiar with so that they can write the best readable code possible without any bugs.

The other implementations in other languages are usually done by other developers doing it as volunteers to let readers of the BIP choose whatever language they like to understand the algorithm better. If a BIP doesn't have other implementations it just means there weren't any volunteers yet and you can act on it if you want to contribute.

This is very weird indeed.
It seems that the Electrum node running bitcoin core thinks that your transaction has a weight bigger than 400,000 and rejects it with a tx-size error message and your Electrum client translates it to The transaction was rejected because it is too large (in bytes)..

I can't find this particular error anywhere else.

P.S. blockcypher explorer usually bypasses some of the standard rules and it pushed the tx but it doesn't seem to be propagating well https://live.blockcypher.com/btc/tx/21f045ec1677f98f6d94503742b1a871aefd75499ceb6f5a5fbd32643ab3d5d5/

P.P.S. Looking at your transaction, it is too small (78 bytes stripped). You should add more bytes to the OP_RETURN output to increase it to at least 82 bytes. This is the actual reason why bitcoin core's mempool rejects your transaction.

I haven't tried that many wallets either but the handful I've seen didn't have any option to import a single key, they only accept mnemonics and derive all keys on demand in a tabbed design. For example you ask for a new address it shows a new page with 3 tabs each showing a different address type with a different derivation path for p2pkh, p2wpkh-p2sh and p2wpkh.

I ran the transaction with its UTXO through a verifier and it failed on OP_CheckSig with the reason being invalid ECDSA signature. Everything else (scripts up to OP_CheckSig, amounts, tx size/weight) is fined though.

Probably, but I used my own code.

Not "consumers" but "traders". The tax is also targeting the profit that the traders are making from trading cryptocurrencies, some of which is massive amount of profit which paying a high tax on it won't even bother the profit maker.
Other than that Japan has 0% tax on bitcoin payments. In other words a merchant or a customer who are using bitcoin for payment pay no taxes whatsoever while they have to pay taxes if they accept fiat.

You are wrong and since you like to use USD values I'll give you USD values.
When bitcoin started miners were earning $0 per block. We fast forward to each time the money they earned was cut in half (dropped 50%):

• 2012-11-28 they were earning      $75 per block
  
• 2016-07-09 they were earning   $8,500 per block
  
• 2020-05-11 they were earning  $61,875 per block
  
• 2021-03-09 they are  earning $309,525 per block
  All the above values are with 0 fees per block!
  
  Although the price rise is not guaranteed but there is also no reason for the growth to slow down let alone stop. So historically speaking we have no reason to believe hashrate would drop just because profitability of mining bitcoin would decrease.
  
  You also make the mistake about hashrate; it doesn't rise only with price (profit miners make) but also it increases with advancement of the hardware used to mine bitcoin (ie. new and more efficient ASICs).

I never said "it is going to end up being a currency"! Bitcoin IS already a currency. In fact the only reason why it can also be considered a store of value, etc. is because it IS a currency which is its main utility that is giving bitcoin its value.

People have been using it for payments for a very long time. For example Bitpay used to report $1 billion worth of payments processed (>90% of it was bitcoin) annually last time they released the number which was before they stopped (right after they got their virtual currency license from the New York Department of Financial Services). And that's just BitPay which is not the best service to use, it is centralized among other issues. There are a bunch of payment processors and merchants can always accept bitcoin directly.

In other words bitcoin has been fulfilling the role of a currency in range of trillions of dollars every year.
The fact that there is a small rise in number of people who are making payments with shitcoins doesn't change the fact that the above number about bitcoin payments is growing tremendously.

For someone who has to ask others what to do, 20% is also high and 80% is definitely a big NO. In the end it is up to you to decide how much risk you are willing to take and when you are trading and worse (taking bigger risks with futures) you are taking big risks and you should allocate your funds based on that and not based on how much profit you wish to make.

It depends. Is 10k all the money you have and more importantly can you afford to lose it? If the answer is no, then decide how much of it you can take risk on and then invest that much.

Since you seem to be new to this market and specifically because of what you said in this quote, you should only go with bitcoin since altcoins have manipulated market that only pumps and dumps and they don't have long term potential so they are only good for short term trading for those who want to take very high risks. But bitcoin has a much lower risk and it is the only thing that is actually useful and has a solid future.

The Lightning Network features are optional features that you can choose to not-use and they have no effects on the rest of the Electrum wallet's behavior. It is not only safe but also it is best to upgrade to the latest version since it has many improvements and some bug fixes that may affect you depending on your usage.
However make sure to always have a backup of your mnemonic so that you can always recover your funds in case something went wrong whether during the update or any other time.

You messed up some decimals there.
The last transaction has one input with the amount = 0.00010000BTC and there is one output with the amount = 0.00005000BTC.

The problem with this tx is not its amount but its invalid signature, which is either because OP's signing function is buggy or OP's calculation of the sighash for signing.
I'm betting it's the latter so here is what sighash should be in case OP wants to double check: c8d3c14a3b190b6ea53ce4317fdd51ca1cf1a235dffbc3ce566507061f901a5a