29 C.F.R. § 2580.412-4

The affirmative requirement for bonding persons falling within the definition of administrator, officer or employee is applicable only if they handle “funds or other property” of the plan concerned. The term “funds or other property” is intended to encompass all property which is used or may be used as a source for the payment of benefits to plan participants. It does not include permanent assets used in the operation of the plan such as land and buildings, furniture and fixtures or office and delivery equipment used in the operation of the plan. It does include all items in the nature of quick assets, such as cash, checks and other negotiable instruments, government obligations and marketable securities. It also includes all other property or items convertible into cash or having a cash value and held or acquired for the ultimate purpose of distribution to plan participants or beneficiaries. In the case of a plan which has investments, this would include all the investments of the plan even though not in the nature of quick assets, such as land and buildings, mortgages, and securities in closely held corporations. However, in a given case, the question of whether a person was “handling” such “funds or other property” so as to require bonding would depend on whether his relationship to this property was such that there was a risk that he, alone or in connivance with others, could cause a loss of such “funds or other property” through fraud or dishonesty.