Excess Marketable Securities is the "last" use of funds in case of cash surplus. When all funding instruments are reduced and there are funds remaining, Excess Marketable Securities accumulates excess funds. This account also acts as the first funding source under the default setting in case of cash deficit.
Similar to Long-Term Debt: Excess, most attributes related to this account are unchangeable. Excess Marketable Securities cannot be subaccounted. It has an unlimited maximum. A minimum balance cannot be specified and the Apply Cash Surplus to... and Fund Deficit with... orders cannot be changed.