With a few exceptions, you must always prove that the funds you are paying with are yours or are gifted to you. The source of the funds must be shown. So if the funds are yours, they should be in a bank account, stocks, bonds, etc. If they are being gifted to you, then the one giving you the money must show the same proof of the ownership of the funds he or she is gifting. Then, when the money transfers to you, the paper trail of the transfer must be shown to Fannie Mae. Generally speaking, yes you should have the funds for 6 months. Exercising stock options or cashing in stock after your company goes IPO or gets acquired are not actual exceptions because you owned the options or stock before you converted them to cash equivalents. There are exceptions to needing 6 months seasoning (holding the funds for 6 months) such as receiving an inheritance, winning the lottery, and the like.
You can cash out from your investment properties to buy your home. That means re-financing your investment properties with a cash out loan. This isnot an exception to having the money in the bank for 6 months. The source of the money is your property and you've owned that property over 6 months, so that shows you have owned the money for over 6 months.
I would be happy to re-finance your investment properties and assist you with arranging the lending for your new home, as well as help you find your new home. You can call me, Mitchell Pearce, at 408-639-0211 or email me at firstname.lastname@example.org
God Speed to your plans.