It depends on your investment plan and affordability. If your money is temporarily idle, keep it. Anyway, the market is already very low now, and the difference can't be worse. When the large-cap stocks in the market go up, so will your fund. But if you can't bear the loss it gives you now, you are willing to admit defeat, sell it and leave the bag peacefully.
I suggest you study the index of the oversold market in Shanghai Stock Exchange. If you think it has gone up in the market, wait, otherwise, sell it.