This will be a short article, and relevant only to the current situation March 5, 2021
Summary: Custodial solutions aren't ideal, but sometimes you have no other choice if you want to be an early mover. Yes, not your keys, not your crypto, but as you'll read below, there are sometimes reasons for holding BTC through Grayscale Trust. Right now, there is a massive arbitrage opportunity going on RIGHT NOW. BTC and ETH are 10% off on Grayscale's Crypto Investment Trusts.
Specific example of how to take advantage of this:
If you're like me who tried every possible BTC/crypto app at first launch, you may have purchased BTC/ETH on Robinhood. Robinhood is user-friendly, but it's early promise to allow for withdrawing crypto never came to fruition. I've been frustrated that I even used Robinhood when other solutions now allow for full control of your own crypto, and at worst, a much higher interest rate than Robinhood (Celsius is my centralized app of choice for holding, earning 5-10% APY on my crypto, compound interest. Ref Link if you want to support:15399575b5
If you're also like me, you probably wanted to purchase or did purchase Grayscale's BTC notes, which typically cost 10%-30% premium. For me, I wanted Bitcoin in my Roth IRA, because the long terms gains of Crypto could be tax free. 20 years down the line, and this could be a big deal! And so Grayscale long term was the easiest and best solution (at the moment).
(I even accidentally bought ETH at 10x the normal price through Grayscale, when it first launched, not knowing that shares did not equal 1:1 ETHE (Grayscale ETH) to actual ETH...Lessons learned). Do your math and do your research before purchasing is all I can say.
But now, for the first time ever, both BTC and ETH are at a massive 10% discount.
So, here's what you do.
Sell your BTC on Robinhood, and buy Grayscale's BTC, and pocket the extra 10% (watch your capital gains tax). Done! Now you can withdraw your Robinhood funds as cash, and have your BTC, in my case, in my retirement fund.