How to determine if you are borrowing funds from IB

If the aggregate cash balance in a given account is a debit, or negative, then funds are being borrowed and the loan is subject to interest charges. A loan may still exist, however, even if the aggregate cash balance is a credit, or positive, as a result of balance netting or timing differences. The most common examples of this are as follows:

1.       Long vs. Short Currency Balances – accounts holders may borrow cash denominated in one currency if it can be secured by a credit balance in another.  Take, for example, a USD base currency account holding a long USD settled cash balance of 10,000, a short EUR settled cash balance of 5,000, with a EUR.USD exchange rate of 1.38:1. Here, for statement reporting and interest computation purposes, the overall cash balance is a USD credit of 3,088 (10,000 – (5,000 * 1.38)). As each currency is subject to a unique funding and reinvestment arrangement, the short balance would be subject to financing costs based upon its benchmark rate and tier. This cost may be offset by any interest earned on the long balance based upon its benchmark rate and tier.
2.       Gross Balances by Segment – IB’s Universal Account contains multiple sub accounts or segments, each of which holds positions and collateral which, for regulatory and customer protection purposes, may not be commingled. This separation does not allow for netting of balances across segments and a credit in one segment may therefore not offset a debit in another. Take, for example, an IB LLC account holding both securities and commodities positions with the securities segment maintaining a debit cash balance of USD 3,000 and the commodities segment a credit cash balance of USD 8,000. While the account holds an overall net credit balance of USD 5,000, the short balance would be subject to an interest charge which may be partially offset by any interest earned on the long balance.
3.       Short Sales – a short sale is a margin transaction in which the account holder is borrowing stock rather than cash. While the proceeds from the short sale are credited to the cash balance of the account, these funds must be posted with the lender of the shares as collateral to secure their return. As a result, and in recognition of the fact that the loan transaction is subject to its own financing terms, the cash collateralizing the loan is excluded for the purpose of determining whether a margin loan exists.
As example, consider an account reporting net liquidating equity (all balances in USD) of  9,000 comprised of a credit cash balance of 4,000, long stock valued at 10,000 and short stock valued at 5,000. In order to determine whether funds are being borrowed to finance the long stock position, the 5,000 portion of the cash pledged as collateral to the lender of the shares is deducted from the overall 4,000 cash balance, resulting in a 1,000 debit. This debit is subject to interest charges and the cash underlying the stock borrow either an interest charge in the case of hard to borrow shares or a short stock rebate if the shares are easy to borrow and reinvestment rates sufficiently high.
4.       Unsettled Funds - borrowings are determined based upon settled funds and the timeframe by which payment is due or received for a given transaction is product specific (e.g., stocks generally settle in 3 business days, spot currencies 2 and derivatives 1). For statement and trading platform purposes, cash balances are reported on a trade date rather than settlement date basis, as if settlement has completed.
As a result, an account reporting a credit cash balance may, in fact, still be carrying a margin loan if that balance includes proceeds from the sale of stock purchased with borrowed funds awaiting settlement. Similarly, an account may report a trade date based debit balance, but not yet incurring a margin loan and interest charges, as the trade has not yet settled.
For additional information regarding interest calculations, please refer to How Interest is Calculated.