taking gold as an example
imagine gold as box one. has its own market.
imagine gold ETF as box two. it has its own market too.
also inside box two are 4 more boxes and each box has their own market also.
now imagine you want to buy something in box two. you will NOT be handed the contents of box one.
box two only contains paper with statements saying that box two may or may not have links to something that is in another box.
but stipulates you cannot physically have the other box, you can only trade the paper statement.
box two trading does not affect the supply or demand of box one.