Mostly on bullion. Just look at a half-day or something. The precious metals especially. Usually at night and on US holidays (the markets trade 23h/day - Hong Kong, Sydney), and this is when they make billion-dollar orders...
That is when order books are empty.
Volume plays a large role in things. The less real volume, the more easily manipulated (in the short term - but do it enough, and there's long-term effect too).
Most manupliation is made possible by leverage too. Leverage is the big fish's tool. It's why you sometimes see huge 'ripsaw' swings. That's algos determining they can 'spend' millions to 'earn' billions, with just a quick, artificial squeeze.
It's also why 1 or 2 central exchanges are bad. When you can see everyone's 'max pain' (liquidation points), then it's like having your own money tree. All you need to do is employ the shakedown.
Watch, Thanksgiving is coming up. Gold should be over $2k then. US markets will be closed. It will get smashed down big, a huge candle. Bet on it! I will tag you and show you. They will bring it down 3% at least.
I know it doesn't have much to do with anything. But it happens all the time and no one talks about it.