Missing Gold is most often caused by accidental purchases. Common accidental purchases include crafting recipe buyouts, gift spree buyouts and decor / clothing collection bundle purchases.
You can minimize the risk of an accidental purchase by avoiding clicking buttons with the Gold bar image on them.
If you are concerned about your gold total, please open a support ticket. Our customer service agents can help you understand where your gold has gone, and may be able to offer you a refund.