A part of the Commerce system in Black Desert. One can exchange money into gold ingots or gold bars and potentially make a profit via workers and Investment Banks.
This is done at Storage Keeper ("Currency Exchange" button) and there is a 0.1% fee. Gold bars with a value of 100.000 cost thus 100.100 silver while 10G gold ingots are sold for 1.001.000 silver.
The gold ingots can be deposited with the Investment Bank - but the bank is based on Housing reputation ... it does business with you only if you have the top rank in a residence you own. That means you need to own one house/room which is decorated with furniture or such in a way that it gives you the top rank of this house. Of course you can always open a residence in a spot nobody else wants to own a residence and then put little furniture into that one ... voila, top rank in an owned residence.
You receive a certain interest for the gold value you deposit with the investment bank. Investments aren't always a safe trade; they are a bargain, as gold can be lost through unsafe investments. The interest varies depending on the risk. To start investing, you need to have the mentioned top residence rank. Place the gold into your storage. A Dollar sign shows on the map at certain nodes (for example Northern Wheat Plantation, Florin or Calpheon). Chose which investment bank you want to invest in (for example Lasquean Ljurik Investment Bank). Then you need a worker in that location - the work speed and maybe his luck seem to improve the outcome of the investment.
Send the worker to work on this node and hope for the best. At workspeed 65 it takes roughly 14 hours to know if you made profit or not. Interest rates vary between -9% and +19% it seems.
Other uses of Gold
Other uses of gold are: weight reduction when moving money. Gold can not be traded between player.