Sometimes you don't need insider trading knowledge. As it goes, that if any broker executes a trade that large, the DTC will have to settle it. Everyone will pretty much see it. Such as how market value flows and goes. A sell will make the stock/investment take a bear position. A buy will make it take a bull position. It's easy to have such large money movement influence the stock market. Cuz they also look at actual cash position in percentage to invested dollars.
So there's a trick for them to do it. It's called something like a conversion. Cuz they aren't executing the buy/sale on the open market. tsk tsk tsk. sneaky bastards.