Pay attention to Opinion, because you can farm points for free.
Why? In short, it's a project from CZ, essentially predictions on the BNB chain with no competition. The volume is still small, so the growth potential is huge.
Currently, the trading volume is only ~$100M, but if Binance promotes it, the scale could be wild.
How to farm without spending money:
Split — you buy a position directly from the contract for any amount. You can invest a lot of capital, earn points, and be delta-neutral. If the market closes, the funds will be returned.
Playing on the spread - you place a bid/ask, take margin from users who don't understand limits and Split.
Hybrid Split - you open a position through Split, then place it in the order book for “foreign” orders that will not be executed, and farm points.

