All bullion in storage is audited on real time basis. Additionally, all incoming and outgoing bullion is monitored with the full oversight of local customs authorities. Physical available bullion balance is reflected real time in your account.
Related articles:
Where are my bullion physically stored?
What is the fee for storage per year?
Can I visit my bullion and withdraw in person?
Are my bullion holdings fully insured?http://help.stackermarket.com/en/articles/5355742-are-my-bullion-holdings-fully-insured