Polkadot is a good project backed by solid fundamentals. It was created by one of Ethereum's co-founders (his name is Gavin Wood). With parachains technology, Polkadot will be able to scale to millions of users worldwide. It can rival competing smart contract platforms such as Polygon (MATIC) and even Cardano (ADA). You can start by buying small amounts of DOT to begin staking for profits. If you keep accumulating, you'll obtain big rewards in the long run.

I can't recommend Polkadot or any other cryptocurency for short term profits because the market is in a very bad state. Just focus on solid projects that actually provide real use cases to the mainstream world (like Polkadot and Polygon), and you'll have nothing to worry about. Who knows what the future holds for the entire crypto/Blockchain space? Just my thoughts