So I see, on t.v. and movies, guys in suit screaming in a super crowded room 'buy buy buy! Sell! Buy!'.
How does this work? Who's keeping track of selling and buying?
And if I own stocks in oil, why does my money in oil increase in value? Like if I buy a barrel of oil for $30, it doesn't stay in a warehouse for decades untill I want to sell it. So who keeps track of who owe what barrel of oil?