Interest and Financing


Interactive Brokers follows the steps listed in the Calculations section below to calculate the daily interest payable or receivable on cash balances. Interactive Brokers will combine, where possible, the balances held across multiple account segments of the Universal Account; however balances across multiple Interactive Brokers accounts will not be consolidated. In the event you hold an account with Interactive Brokers Canada or Interactive Brokers Securities Japan, the calculation will be EndingSettledCash – ShortStockCollateralValue only, as there is only one account segment.

Step 1

At the end of every day, IB will obtain the following balances in each currency:

  • Ending Settled Cash balance in the securities account segment
  • Ending Settled Cash balance in the commodities account segment
  • Collateral balance for settled short stock positions
  • Ending Settled Cash balance in the IB-UKL segment
  • Commodity risk margin requirement

The cash balances are reported on the Daily Statement under Ending Settled Cash. The commodity risk margin requirement is the Maintenance Margin Requirement as reported on the daily Margin Report minus the total commodity option value.

The collateral balance per short stock is calculated by multiplying the prior day's closing price by an adjustment factor based on the currency, rounding this value up, then multiplying by the number of shares.

For example, the collateral balance on a USD-denominated security would be:

Collateral Balance = (stock A prior day closing price x 102%, rounded up to the nearest 1.00) x (number of shares stock A) + (stock B prior day closing price x 102%, rounded up) x (number of shares stock B)

The adjustments utilized by IB are as follows:

USD-denominated stock – multiply by 102%, round up to nearest 1.00
CAD-denominated stock – multiply by 102%, round up to nearest 1.00
EUR-denominated stock – multiply by 105%, round up to nearest 0.01
CHF-denominated stock – multiply by 105%, round up to nearest 0.01
GBP-denominated stock – multiply by 105%, round up to nearest 0.01
SEK-denominated stock – multiply by 105%, round up to nearest 0.01
AUD-denominated stock – multiply by 105%, round up to nearest 0.01
HKD-denominated stock – multiply by 105%, round up to nearest 0.01

Step 2

IB will obtain the USD-equivalent Net Asset Value in the account, consolidating the equity across the IBLLC and IBUKL accounts where possible. The Net Asset Value (NAV) is reflected in the daily account statement under the same name.

For the purposes of crediting interest on either long settled cash balances or short stock collateral values, only accounts with NAV exceeding USD 100,000 will be eligible to receive credit interest on long settled cash balances.

For example, if an account holds

  • Settled Long Cash 370,000 EUR
  • Settled Short Cash (370,000) USD

Calculate the USD-equivalent of the EUR balance = 370,000 x 1.2 = 444,000

Calculate the USD NAV = 444,000 – 370,000 = 74,000

As the account would not meet the USD 100,000 requirement for credit interest, no interest would be paid on the long EUR cash balance. Interest would be debited on the short USD cash balance.

Step 3

IB calculates an Adjusted Cash Balance for the universal account by combining the Ending Settled Cash balances for the securities, commodities and IB-UKL segments and subtracting the commodity risk margin requirement as well the short stock collateral value. The commodity risk margin requirement is removed from interest considerations as this represents margin which may be put up at the exchange rather than being considered free funds.

AdjustedCash = EndingSettledCash_Securities + EndingSettledCash_Commodities + EndingSettledCash_IBUKL – ShortStockCollateralValue - CommodityRiskMargin

Step 4

IB will then determine how much of the AdjustedCash balance should be applied to each rate tier (see tier tables). Finally, we calculate the interest using the applicable rates (also from the tier tables): 3

The numberOfDaysInYear are based on industry standards for money market activity.


Interest = ( Balance tier1 * Rate tier1 / numberOfDaysInYear )
( Balance tier2 * Rate tier2 / numberOfDaysInYear )
( Balance tier3 * Rate tier3 / numberOfDaysInYear )

Accruals will be posted to the applicable account segment as follows:

If the cash balances of (security+commodity) and IB-UKL segments are the same sign (i.e. both positive or both negative), the interest of the universal account will accrue to the security and IB-UKL segments on a pro-rata basis.

If the cash balances of (security+commodity) and IB-UKL segments are of opposite sign, the interest of the universal account will accrue to the segment with the higher balance.

The results of the above calculations are booked to a special "Accrued Cash" sub-account, one for each currency. Accrued Cash has the following features and functions:

  • FUNDS FOR TRADING: accrued cash is applied to trading balances, both positively and negatively.
  • WITHDRAWALS: accrued cash does not affect Settled Cash balances and therefore cannot be withdrawn. Positive accrued cash balances do not increase the available funds for withdrawal. However, negative accrued cash will reduce the funds available for withdrawal. This avoids the problem of having closed accounts with negative balances.
  • PATTERN DAY TRADING: accrued cash does not count toward Pattern Day Trading minimum balance requirements.

Everyday, the new calculations for accrued interest are added to the cumulative accrued cash balances from the previous day.

Statements: Whenever the balance of accrued cash exceeds $1.00 (or USD equivalent), we will show the accrual on the Daily Statement. Accruals smaller than $1.00 are recorded in the IB systems but are not reported on the statements.

At the end of the month, or within the first few days of the following month, IB follows these steps:

  1. IB recalculates all the interest amounts using the calculations above. The new calculation is usually identical to the original cash accruals but may vary by small amounts due to corrections in settled balances or rates.
  2. IB determines the cumulative accrued cash for the previous month as the sum of the individual days.
  3. IB reverses this amount in the Accrued Cash sub-account at the beginning of the following month. For example, if the accrued cash balance for July was positive, we apply a debit charge to accrued cash in early August.
  4. Simultaneously, we book the final interest calculation from Step 1 above to the regular cash account. In effect, Steps 3 and 4 above convert "pending cash" to "actual cash."
  5. These transactions 2 are reported on the Monthly Statement.

Trade Date versus Settlement Date (or Value Date)

In most large financial transactions, there is a time delay between the date on which the transaction is agreed to, and the date on which it settles, i.e, when the actual payment occurs. In the case of stocks (for example US stocks) there is a three business day settlement period. If the trade is executed on a Monday, under normal settlement conditions the actual transfer of money occurs on Thursday. If the trade occurs on Wednesday, three business days later crosses the weekend so normal settlement is the following Monday. Exchange and banking holidays the fall within the settlement period will push back the settlement date.

Why is the Settlement Date Important?

Only settled money is considered for interest rate purposes. When one buys stock, one retains the rights to interest on the money until settlement date. Similarly, sellers only start to receive interest beginning on settlement date.

Settlement Dating is generally a minor consideration for stock, option, and future traders. However, due to the large amounts of capital involved, understanding the concept of Settlement Dating is critical to FOREX and fixed income (bond or money market) traders.

  1. The new accrued cash shown after the above postings may not be zero. The residual balances reflect the continuing accruals for the first days of the current month. For example, if IB processes the final interest calculation on August 6, Accrued Cash will still show the activity from August 1 through August 6.
  2. Interest will not accrue or be paid to the commodity segment of the account. Both credit and debit interest will accrue and pay to/from the securities and IB-UKL segments.
  3. The calculated interest per tier will be rounded to the nearest 0.01 (or 1 for JPY). Therefore, a calculated interest of USD 0.0051 will be rounded to 0.01.