The big money is not in the buying and selling ... but in the waiting.
A banker who is allowed to borrow money at X and loan it out at X plus Y will just go crazy and do too much of it if the civilization doesn't have rules that prevent it.
Intelligent people make decisions based on opportunity costs.
Step by step you get ahead, but rarely in fast spurts.
It's been my experience in life if you just keep thinking and reading, you don't have to work.
No wise pilot, no matter how great his talent and experience, fails to use his checklist.