What are the legal recourses for me in the case of having a family member fraudulently take a securities account out of my possession?

       You would have the right to sue your family member claiming they committed a fraud against you or engaged in undue influence by coercing you or forcing you to sign legal papers transferring your financial interests in your investments at a time when you may have been mentally incapacitated or otherwise incapable of understanding or knowing what may have been going on with you at the time from a medical perspective. You would have to prove fraud by clear and convincing evidence. It would also be helpful to know what they did with the money and whether it still exists or they have spent it. You will be hard pressed to find an attorney who will be interested in pursuing a case like this, without a substantial retainer paid up front and your paying hourly fees for the representation. That is just my opinion of course.