Ok, it goes like this. King is lowers the silver content of coins, so he can make more coins with silver. A group of merchants learns about it and starts to spread a gossip around that silver in the coin is going up, so people would start to sell their old coins and buy shitty new coins, thinking they make a profit. Then original party was going to buy all the old coins cheaply and sell them to the king for some previleges (no idea here) and for money.
I think thats what was it.
But the outcome was a real letdown for me. I would expect profit in thousands, if not tenth of thousands. Its like they worked for almost nothing.