Uh yeah, predicting the future is the entire idea. People are always guessing what the price is going to be in the future. If you guess correctly you make money when you sell later. If you don't, you lose money. Lots of people are highly incentivised & therefore trying really hard to predict the future, and this is what makes capitalism an efficient resource allocator. That's not only true of metals exchanges. If you think the price of copper is going up, you could also survey for and build a copper mine. That knocks on to labour markets, as you're now hiring miners. So the market's predictions can move the price of everything, and everything readjusts itself to match, all on its own, and finds itself ready (i.e. a whole mine built & ready to go) for when the prediction comes true, or adjusts itself back when it doesn't. The effect of efficient resource allocation + predictive power is that when e.g. supply goes down but demand is up, people have tried to predict this and have already built capacity for more supply. This is pretty fundamental to how most of the world works.

Markets function in general terms as information -> price machines, where people are rewarded for seeking out information and converting it into prices by moving money. If you HAVE INFORMATION that suggests copper's going to go up in value, you buy copper, and because you did that, it DOES GO UP A BIT. So the information becomes a price signal, in advance of the event that actually affects copper supply/demand. If you predict a supply/demand change, and then your prediction "comes true", the price moves, and you can sell at a profit. Magic. You are rewarded for predicting, and in exchange the market learns the correct price a little bit earlier by incorporating your "bets" in the market price. This is known as news being "priced in". Every single day watching financial markets involves big news that some analyst at a bank mispredicted, and then the price has to move a little further or a little back to correct the value it had "priced in". Sometimes announcements come in as predicted, and the markets barely react at all, even to a huge profit announcement. It's because they already knew. They predicted it.

As people "share" the information they have about the assets in the market by buying and selling, the price walks about as it discovers its value. On short timescales, this fluctuation is largely made up of people fretting about really tiny predictions in a capricious and flighty way. The most valuable information, i.e. the stuff that will let you buy in lowest and sell highest, is information the market doesn't know yet. Only some of the information is revealed by buying/selling, as it's a weaker signal than the prediction actually coming true & being reported as news. The creation of newsworthy events happens slowly, much slower than people can trade. People can make a lot of money doing insider trading, because they can predict the future value very accurately & without trades sending a huge signal as they're anonymous! But everyone agrees it's unfair to everyone else, so it's not allowed.

All the people playing this game are trying to predict, because predictions are more lucrative than current information that the market already knows. But they can also be wrong. Fortunately the price of an asset is the aggregate of everyone making predictions, and this averages out to a more useful summary of "what do these 300,000 people think" rather than "one dude at one trading desk". The "invisible hand of the free market" is the emergent wisdom of a whole lot of people trying to guess what's going to happen in the future. And it is pretty wise -- capitalism is actually pretty good at resource allocation to projects that are going to be most useful in the future. It performs better than a Politburo at this task. The main criticism of it is not that it's bad at this job, but that it is too good at it -- and too ruthless at exploiting the information it has to the detriment of the poor humans without much capital at the bottom.