My advice...
1) Seek the advice of an attorney who specializes in family law and divorce, with some estate planning thrown in.
2) Have a pre-nuptial agreement drafted, and have your fiance go to an attorney of her choosing to review it. Offering to pay for her attorney is fine.
3) Maintain a separate bank account in your name, and have the bank add "LDP Separate Account" to the address line, so that it appears under your name (LDP are your initials, change as needed). Have her do the same with her existing separate account (this is very important - it must be bilateral and not just unilateral). You may, if desired, both set up a joint account to pay joint bills out of. You may, as needed, fund the joint account by transferring money from the separate accounts according to a ratio you come up with. If you do come up with other than a 50/50 ratio, it should be carried forward toward the future valuation of joint investments, should you part ways.
4) Maintain separate existing assets and property separately, including your 401K or other retirement and brokerage accounts. That means do not deposit joint money into the accounts... and do not withdraw separate money from them into a joint account.
5) If at some point, she has children, all bets are off and these tips basically get tossed out the window.
6) If you are wealthy, have a foreign corporation set up (I am partial toward Panama, due to corporate filing and officer secrecy laws) to bill you for the "trading advice" you receive... and pay their invoices on time always.
7) Encumber your property by taking out an equity loan from an LLC which is owned by the Panama corp. On the books, it will appear as if you have zero homeowner equity. However, the corporation may allow its loan to be subjugate to any other loans you need to take out, so you can still hypothecate the equity as needed.
8) I could go on and on, with auto lease-back, trusts and estates, and an asset management company that you are indebted to... but I'd rather you pay for professional advice if you truly need it.
Another VERY IMPORTANT thing to keep in mind... regardless of the law, your divorce judge is ultimately the one who determines how your assets are divided. He has jurisdiction over any assets in your name, regardless of what anyone tells you... even assets in a non-revocable or charitable trust. He can reverse any process that you create, if he thinks the intent and purpose of that process/entity was to shield your assets!
A judge here in the USA, however, cannot force a foreign corporation to give up assets (unless you control or are a part of it), nor is his judgment decree valid in a foreign country that does not have a reciprocal agreement with the United States. Panama. Invest in foreign businesses (that ultimately fail). Understand methods for transferring wealth, and their legal implication.
