Portfolios with margin purchases can be handled by making BUY transactions without full matching DPF transactions to compensate for the purchase amounts.  Margin interest payments are entered using the IOB transaction with a negative amount:

 

 

This will cause CASH in the position records to go negative to the extent margined as follows:

 

 

 

Advanced Margin Accounting

 

Margin accounting with maintenance of sub-account detail as required by the U.S. SEC for broker dealers is offered in Captools/net Pro, Level 4, or equivalent Enterprise level program versions.  These support tracking of cash vs. margin sub-accounts through use of a "Cash/Margin" field in the transaction and position records.   These program versions also support computation of credit/debit interest on positive and negative cash positions respectively.  See the topics B/D Margin Accounting and Credit/Debit Interest in the Advanced Appendix for more details.