I know some guys made profit through arbitraging. They will usually look for some 'not well known' brokers where their prices differ from the other brokers.
Some took advantage of the price delay. Some brokers are slightly slower than the other brokers. You can also exploit this. The bad side is, some brokers will ban you if they found out. So you got to check with your brokers if they allow this kind of trading.
On how to exploit this, whenever you see a price difference you will have to buy on one broker and sell on the other, simultaneously.
You have to make sure that the difference should value more than your spread, commissions, and other costs (if any).
Thank you will look into it