(Pro 22:26 KJV) Be not thou one of them that strike hands, or of them that are sureties for debts.
The literal meaning of the Hebrew is given by the KJV in “strike” (8628) “hands” (3709). I guess it could be clap hands. This could be where we get the idea that a deal is not finalized until we shake on it. That really is a side issue though. The core though here is to not get into co-signing a loan. I would think that in an age of capitalism there might be some questions about buying stock or investing in new issues. Venture capitalists would need to think seriously about how this applies to them.
This could be understood to not co-sign on a loan for your son’s car. In addition to protecting you from loss, it might also be important because it would teach the young man responsibility. It is probable that if he cannot qualify for a loan he does not need the car.
So? Our financial commitments come under the title of holy living, just like everything else.