Why Oil Prices Go Up and Down?

Why do stocks like m and c v x go up and down with the price of oil? Is it because they also own so much oil that when the price goes up, their underlying assets go up as well? Or is it because they somehow increase margins by selling for more than their relative increase in cost? Or something else completely? I ave often wondered the same about banks and interest rates. If rates go up, then banks lend for a higher rate, but they also borrow for ahigher rate. So where is the increase in profit coming from? Thanks, as always.