There's a total of ~1,300,000 BTC available on all major exchanges according to viewbase.com with sell offers spanning from 42000 to 100000 and probably higher in the order book. So I'd guess if we pick average price of 70000 per BTC you'll have to pay ~$100 billion. But it shouldn't be as cheap as that because markets will react to such rapid buying and adjust their offers up in price. Or you could start buying... Source: over 2 years ago

Some places (https://swanbitcoin.com for example) allow you to submit an XPUB and use that to automatically generate a new address for each withdrawal. If your platform doesn't allow this, and you want the privacy, you can approximate it manually by just changing the withdrawal address each time. If you don't want the government to know your totals, it's important that you use a platform without KYC. Even if you... Source: about 1 year ago

Also given OP is well into the >1BTC club, Swan would be a decent option for them too. Source: over 1 year ago

But, it sounds like you're looking more for ways to onboard into BTC.... well, there are many exchanges etc but in my opinion Swan Bitcoin is the simplest and most straightforward. You can use my membership link here https://swanbitcoin.com/wsdmrtst or if you don't trust my link just go to swanbitcoin.com. My link is just for me to get a little credit for referring people (it takes you to the same site), but... Source: over 1 year ago

If you're in the US use https://swanbitcoin.com, set up your savings plan (DCA) with them and withdraw for free to your own custody any time. Source: over 1 year ago

Https://swanbitcoin.com is beeing build by bitcoiners for bitcoiners to do that. Source: over 1 year ago