* My wife and I were buying a new house. Since our old one hadn't sold yet, we arranged to sell some investments and had the money funneled into our checking account a month in advance because I knew about the wait time requirements. On the closing day, we arrived at the bank an hour earlier than needed, just in case, because I knew we had to produce a check for the remainder of the sales price, and it was going to be on the order of $200,000.00. When we requested a cashiers check for the amount, even though the money had been sitting in the account for a month and was clearly marked as available on their terminal screen, they just about flipped their collective lids, brought out three extra sets of paperwork, and had to get the check approved by a 3rd-line manager
That's... surprising. I've done this a couple of times, moved >$100k through my checking account to purchase a house, and not once has it set off alarms. It was completely straightforward each time.
One detail that's different: in each case, we wired the funds. No cashier's check, no visit to the bank, just a phone call. The receiving entity was always real estate related, i.e. a title company or an escrow account, and the bank had a pretty good idea what we were doing. Maybe there was some security measures going on where we couldn't see them, but it's never been a visible problem.
Cashier's checks turn out to be a problem for real estate transactions, because for amounts that large, the bank WILL put a 10-day hold on it, despite it being a cashier's check. A receiving bank hates that if if's paying off the seller's mortgage. There's no hold for wired funds, so usually the seller insists on that.
The largest cashier's check I've ever handled was about $75k. The bank teller did have to summon a manager for that, but overall it was pretty smooth, no extra paperwork, and no one flipped out.
Anyway, I didn't raise any objections to Marigold's problem because it's not really the same. The thing about your case - and mine - is that the brokerage had lots of records of the money accumulating over time. Marigold abruptly had large amounts of cash flowing in from somewhere. That kinda looks like it might be from drug dealing or something else illegal.