Make clear what kind of fund you want to buy first. I use stock funds to explain what you asked here. Other types of funds have relatively low returns. Find relevant information to understand the types of funds.

If it is a stock fund, then outperforming the market is the most basic requirement for excellent funds.

From the curve, the blue line should pass through the yellow line and the red line, above the yellow line and the red line.

Below the yellow, the red line means underperforming the market. This level of funding is wired and is not recommended.