TradFi is a derivatives trading product that amplifies returns through leverage. In TradFi trading, you can participate in and profit from market price fluctuations by going long or short on a TradFi trading pair.
If you choose to go long, it means you are buying TradFi and predicting that its price will rise in the future.
If you choose to go short, it means you are selling TradFi and predicting that its price will fall in the future.