There are a lot of potential hypotheticals. Keep in mind that the mining economics is more than just transaction fees. Presumably in the year ~2140, technology and energy could be far more inexpensive relative to current state. Think people tend to only presume transaction fees won't be sufficient while ignoring the rest of the profit equation.

No - the only tradeable investment instrument with bitcoin exposure is GBTC which is Grayscale's Bitcoin Trust. Note that is comes with a very heavy premium compared to just buying and holding bitcoin yourself, but it has the advantage of living in a potential retirement or investment portfolio with your other assets.

To get up and running quickly via mobile with bitcoin, Cash App is one of the more simple and well-known options

This is one of the advantages to having a multi-sig wallet where you need multiple keys to sign a transaction instead of just one. Having a single key represents a single point of failure. Of course you still need to manage your keys in a multi-sig setup, but you don't risk ruin if you happen to lose one of the keys (if for example you had a 2 of 3 setup which means you have 3 keys but need only 2 to sign a transaction).

Lots of options to think about in terms of security. A bank deposit box, safe, home of a close relative, multiple physical locations, etc. Think about the tradeoffs between security and accessibility (more secure may limit accessibility, more accessibility may limit security).

Historically bitcoin has retraced at least 30% from every all-time high as people begin to take their profits. What will be interesting to see with this bull run is if the dips are as pronounced % wise as they historically have been with the increased institutional interest this go around.

Perhaps someone can confirm but I read that Tether purchases account for a very miniscule (~3%) of total bitcoin market purchases?

Coldcard is open source

Coinbase Pro for US customers has some of the lowest fees to sell your bitcoin for USD. 0.5% but you need to be comfortable using a trading platform.

For those interested in exploring more of the technical side of things, the 'Learning Bitcoin from the Command Line' github has helped me understand things in practice versus theory:

https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line

Hopefully I'm tracking the question but the market price for bitcoin is always set to the present. If you bought bitcoin at different points in time, it will always trade at the current market price regardless what you may have paid for them at a certain point in time.

Also there are no blocks that you acquire when you buy bitcoin. Bitcoin is just a giant ledger that keeps track of how many transactions different addresses possess. Your balance is the total sum of all the transactions you've received. The 'blocks' are part of the actual bitcoin blockchain that verifies the latest transaction activity on the ledger.

When the wallet app rotated addresses was the expectation that you had to retrieve your new recovery key associated with the new address?

It is a 'second layer' technology meaning that it is developed as a chain that exists separate yet connected to Bitcoin. The only time I believe that it generates transactions on the Bitcoin blockchain is whenever lightning channels are opened and closed. This is the beauty of lightning because it's ideal for managing all the smaller transactions as a sidechain without bombarding the main Bitcoin network - it only talks to the main Bitcoin network once two lightning channels need to settle up.

I have a pretty simple point of view that boils down to 3 main questions:

1. Do you actually need the cash? (i.e. urgent need without significant fiat savings to cover)

2. Are your current holdings a potential life altering amount? (subjective to the individual)

3. Are you prepared to pay the associated tax liability?

'What to do' of course is unique to the individual based on their objectives and personal situation. I think it's helpful to have a plan at the onset to avoid emotions taking over. If you're a swing trader, then set your targets and act on them. If you're a long-term HODLer, HODL. If you want to do a bit of both, keep your long-term holdings tucked away in cold storage to avoid the temptation to trade.

I’ve had positive experiences with Binance and Bittrex. If you’re going to trade, doesn’t hurt to have multiple exchanges in the event any one might be down.

Binance is a large and reputable exchange so as others have mentioned, you can likely wait and aggregate up to the amount you're comfortable with having on an exchange before initiating transfer so you don't needlessly incur too many fees. I can't recall if Binance requires 2FA (2 factor authorization) but if it doesn't then make sure you have that in place and it's with a reputable authenticator app (not a text message with a code).

Another thing to think about besides the potential for a hack is access in general. Sometimes these exchanges get overloaded when the price of bitcoin moves a lot in either direction.

Kudos to you though for ultimately taking self custody of your own bitcoin!

Bitcoin introduces complexities in two distinct ways. The technology itself is highly complex by design; the complexity that drives bitcoin is what makes the network so secure. And bitcoin besides the technology is a fundamentally new way of understanding money.

The underlying technology that powers Bitcoin will always be complex - it has to be. Satoshi had the following quote, "If you don't believe me or don't get it, I don't have time to try to convince you, sorry" in the early days of building the network. I believe it's vital that those of us who have learned so much along the way and have the time to help others do so. I am a major advocate of ultimately transitioning new bitcoin users towards self-custody and managing their own bitcoin and private keys. I worry a bit once retail adoption becomes very widespread that self-custody will be only managed on the fringes because users are too intimidated to do it themselves - there's an opportunity here to help.

To earlier points, that's a bit on the lower side right now for sure. Another useful website I've used is: https://bitcoinfees.earn.com/

If you scroll down a bit below the chart, there's a 'Which fees should I use?' section. As of this instance for example, this is what it reflects: