What is the difference between them? What do traders at major IBs do? Do they also trade for the firm or do they mainly execute customer's trades? I am just not too sure what those traders at IBs do that make them so much money... Do they generally have larger capital allocated to them to trade so their bonuses are bigger? Do they require higher or more sophisticated math (like stochastic calculus, a lot more modeling and quant analysis) than prop trading business? Why is it hard to go from working as a prop trader to a trader at major IBs? or more generally, why do they look down on us (if any) ?