Small and medium-sized board ETF fund mainly refers to the index fund with listed companies in small and medium-sized board as the investment target. This kind of fund is rare in China market, because the securities market in China is mainly divided into main board, small and medium-sized board and growth enterprise market. Small and medium-sized board and growth enterprise market are relatively small, so the number of corresponding index funds is also relatively small.

Here are some ETF funds that track the small and medium-sized board index:

1. E Fund for Small and Medium-sized Board Index (159902): This fund tracks the Small and Medium-sized Board 300 Index, which consists of 300 stocks with the largest scale and the best liquidity among small and medium-sized board listed companies.

2. Southern SME 300ETF( 159925): The Fund also tracks the SME 300 Index.

It should be noted that the market volatility of ETF funds is large, and investors need to fully understand their risks before investing. In addition, ETF funds may face risks such as tracking error, adjustment of index compilation method and adjustment of constituent stocks. When investing in ETF funds, please be sure to know your risk tolerance, consult professional investment consultants and make wise investment decisions.