I understand prenups for rich people because you never know why someone is really with you, but if you are with someone before getting rich, that is one of the few things you can never have again. If the relationship is good I don't know why you suddenly make it all about money and drive a possibly irreparable wedge between you. And for what? Because if things go sideways you might lose half? Half of rich is still rich and it's a small risk to take for the chance at a lifelong loving partner. Some things are worth more than money.