The first point: Has your husband been successful in business before, or in other industries? If he has, it means that he was confident when he made this investment. He has some experience in some industries, but he is not completely ignorant.
The second point: before investing, is there any money at home for my husband to invest? The purpose of investment is to make money, but if you don't even have the money to invest in the early stage, it is definitely wrong to invest blindly. If you want to make money, you must learn to face the risk of investment failure.
The third point: Do you have a good personal eye? If you have rich experience before and your favorite investment is basically successful, then it is wrong for him not to listen to you. At present, the only truth in this society is that whoever can succeed is right, otherwise it is useless to say no matter how good it is.
So since the loss has become a fact, you can't say let him go. After all, you are husband and wife, and you should share joys and sorrows with your husband to tide over the difficulties.