A great question, one is not allowed to steal from a spouse.
A Husband cannot take a wife's personal property without her consent (קיצור ש׳׳ע ס׳י קפ׳׳ב סע׳י י׳׳א). Each spouse can have their "personal property", especially property brought in before the marriage.
Assuming a spouse took another spouse's property the legal solution (though not ideal) would be to go to court or have a Rabbi determine what can be done. For example in Igros Moshe (אה׳׳ע ח׳׳א סי׳ י׳׳ב) Rav Moshe determines that a charity foundation should return the $2000 dollars to the wife because she had taken it incorrectly from the Husband.
I think in regard to misleading with an investment, this is hard to argue. Although it might be wrong and self-serving and Hashem will punish a person, the Husband though "manipulated" did take a "gamble" as the nature of any investment. Unless there was outright fraud. It is hard to argue an investment will 100% remain the principle whilst gaining profit (such investments don't usually exist). In fact there might be an issue of Ribbis (prohibited like usury) if the principle is secure, but mostly every investment has some likely loss or it might be ribbis. So I can't imagine a court returning the money from a 3rd party to the Husband unless there was fraud. He simply knew when he gave his money he may no longer see it again as the nature of investments. Unless like I said there was something illegal done with money. For example the 3rd party bought a home for the wife's parents and there never was an investment.
I would also say that usually spouses share accounts and so many times this question doesn't or can't come up since the money is either not gone yet, or it is in a 3rd party's hands, which makes it very difficult to reclaim.
Also see שו"ת הרשב"ש (סימן צ"א) where there is a complicated case where a husband leaves to a remote location and his wife rents their rental home (rented for a year) to a 3rd party after the husband left. He comes home and demands this 3rd person leave and that his wife was not entitled to do this. There the רשב"ש answers that it is well known that woman rent and sell without permission of their husbands, and it is normal for a wife to do this. And how much moreso in this case where she was poor and a Husband is responsible for supporting his wife. He rules that the Husband cannot kick this individual out of their house.