How do I sell a stock short?

Procedurally, to sell short, all you need to do is specify your order Action as 'Sell' at the point you create your order. Note that we do not allow you to be both long and short the same security, so if you maintain a long position and enter a sell order, you will close out any long positions to the extent of your sell order and open a short position to the extent, if any, your sell order exceeds a long position. Please note that you must maintain a "Margin" type account with net liquidating equity of at least USD 2,000 for a short sale order to be accepted. Short sales are not allowed in "Cash" type accounts.

Also note, that in addition to your account having sufficient equity to meet the margin requirement associated with the transaction, IBKR is required to meet its regulatory obligation of making a reasonable determination that we can locate the stock for borrowing purposes when the transaction settles (typically T+2). If we are unable to locate the stock based upon our inventory and the availability lists provided to us by other brokers, you will see an Order Status color in the TWS Shortable column of dark green. This indicates that there are no shares available to sell at the moment and that the system is searching for shares. The order will remain in this status until the we are able to locate the shares or the time which you specify for your order to remain in force expires, whichever occurs first. You may wish to review the Shortable Stocks link to our website below which provides a listing of stocks available for shorting. A list of shortable stocks searchable by symbol or CUSIP along with their indicative borrow rates may be found through the Short Stock Availability Tool accessible through the Tools link within Client Portal.

Finally, you should be aware that one of the risks of borrowing stock to support your short sale is being bought in with little or no notice. Even though a reasonable determination that the shares can be borrowed will be made prior to effecting your sale transaction, there is no assurance that those shares will actually be available at the time of settlement or any day thereafter. The supply and demand of borrowable inventory for any given security is dynamic by nature and regulations require brokers to force-close any short position having a delivery obligation subject to fail with the clearinghouse on any given day. We will make every effort to provide you with advance notice if this appears to be the case in order to provide you with the opportunity to buy in your own position, however, this is done on a best-efforts basis. Other risks to keep in mind are the special charges which tend to be associated with hard-to-borrow securities that, in aggregate may exceed any rebate or interest paid on the short stock proceeds, as well as your obligation to pay to the lender any dividends which are paid throughout the duration of the loan period.

Why did I receive a notice that the financial capacity in my account is less than 10% above the current margin requirement when my stock positions are fully-paid?


IBKR will issue a warning message to any margin account approaching a maintenance margin deficiency (and therefore potential forced liquidation of positions).  This message is generated when the Equity with Loan Value (ELV for a stock account = Cash + Stock + Bond + Mutual Fund + Non-US Options) is less than or equal to the Maintenance Margin Requirement * 110%.  The warning message reads as follows: 

ALERT: The financial capacity in this account is less than 10% above the current margin requirement.  To avoid a possible liquidation, please monitor the account to ensure that there is positive excess liquidity.

An account which hold stock positions that are full-paid (i.e. no cash debit) remains susceptible to liquidation if the account falls into deficit and the loan value of the stock is insufficient to cover the debit.  This is often the case, for example, when a margin account holds positions subject to 100% margin and a cash balance of $0.  In the event the account is assessed a fee, such as commission, monthly minimum activity or market data subscription, a negative cash balance would result and IBKR would not be able to extend loan value against these securities to support the debit balance. The account would therefore be subject to a liquidation in an amount sufficient to cover any cash deficit.

Accordingly, the recipient of this warning message may wish to maintain a cash balance in an amount sufficient to cover any potential charges to the account and to avoid a forced liquidation.

What is the meaning of Mark-to-Market and First In, First Out?


Mark-to-Market (MTM) refers to the method of calculating values for positions based on daily movements of the position calculated against the closing or settlement price of the product for that day.  At the end of each business day, the open positions carried in an account are credited or debited funds based on the settlement price of the open positions that day. 

First In, First Out (FIFO) is the practice of using the first initiated position in a security as the trade that is paired off against the most recent closing trade in that same security.  This method is often used for tax accounting purposes.  In other words, it is the method of valuing securities which uses the oldest items in inventory first.

Add/Remove Liquidity


The goal of this article is to provide proper understanding of exchange fees and add/remove liquidity fees for the Tiered commission schedule.


The concept of adding or removing liquidity is applicable to both stocks and stock/index options. Whether or not an order removes or adds liquidity is dependent on that order being marketable or non-marketable.

Marketable orders REMOVE liquidity.
Marketable orders are either market orders, OR buy/sell limit orders whose limit is at or above/below the current market.

1. For a marketable buy limit order, the limit price is at or above the Ask.

2. For a marketable sell limit order, the limit price is at or below the Bid.

XYZ’s stock current ASK (offer) size/price is 400 shrs at 46.00. You enter a buy limit order for 100 XYZ stock @ 46.01. This order will be considered marketable because an immediate execution will take place. If there is an exchange charge for removing liquidity, the customer will be charged that fee.


Non-Marketable orders ADD liquidity.
Non-marketable orders are buy/sell limit orders in which the limit price is below/above the current market.

1. For a non-marketable buy limit order, the limit price is below the Ask.

2. For a non-marketable sell limit order, the limit price is above the Bid.

XYZ’s stock current ASK (offer) size/price is 400 shrs at 46.00. You enter a buy limit order for 100 XYZ stock @ 45.99. This order will be considered non-marketable, because it will be posted to the market as the best bid, and instead of being immediately executed.
If and when someone else sends a marketable sell order that causes your buy limit order to be executed, you should receive a rebate (credit), if an add liquidity credit is available.

1. All accounts trading options will be subject to any options exchanges’ remove/add liquidity fees or credits.
2. Per IBKR’s website, only negative numbers under the Remove/Add Liquidity schedules are rebates (credits).
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What is the exchange minimum margin requirement on SSF positions?


In the case of a long or short SSF, the exchange margin requirement is equal 20% of the underlying value of the contract (initial and maintenance margin)

In the case of a hedged position (e.g., High or Low Synthetic strategy) in which a clilent is long (short) a security futures contract and short (long) the underlying security, the required maintenance margin would be equal to 5% of the instrument having the higher current market value.

Will a long SSF ever trade at a discount to the underlying stock?



When a large dividend payment is forthcoming or if the underlying stock is difficult to borrow, the futures price may trade at a discount to the actual cash price.

Why does a long SSF typically trade at a premium to the underlying stock?



Single Stock Futures will typically trade at a premium to the stock price because of an adjustment for interest rates. The premium reflects the interest earned on the capital saved by not posting the full value of the underlying stock (adjusted for any dividends expected to be received prior to expiration).

How are SSFs priced?



Single Stock Futures (SSF) may be priced using the following formula:


Futures Price = Stock Price * (1 + (Annualized Interest Rate * Days to Expiration/365)) – Present Value of Dividends due prior to expiration.


Example: On 12/12/07 MSFT closed at $35.31 and has an expected dividend of $0.11 with an ex-date of 2/12/07 (61 days).  Assuming an interest rate factor of 4.5%, what is the 12/12/07 settlement price for the MSFT March 2008 SSF (97 days to maturity)?


$35.62 = $35.31 * (1 + (.045 * 97/365)) – ($0.11/(1 + (.045 * 61/365)))

Is a US Single Stock Future a security or commodity product?


US Single tock Futures (SSF) are a hybrid product, regulated jointly by the SEC and CFTC and allowed to be carried in either a securities account or commodities account.  IBKR elects to carry all SSFs in the security side of an account as this is the only way that margin offset can be provided against other security products (i.e., stock, options). 

US SSFs are listed at the OneChicago exchange and are cleared through OCC.

Are there any particular risks that one should be aware of when using SSFs to either invest excess funds or borrow funds at available synthetic rates?


While the High and Low Synthetic strategies are both hedged positions, the futures leg is subject to a daily cash variation of the mark-to-market gain or loss whereas the stock leg is not (mark-to-market gain or loss is reflected in account equity but there is no cash impact until the position is closed).  If, for example, an account holds a High Synthetic position and the stock prices increases significantly, the resultant variation pay on the short futures leg may erode the account’s cash balance resulting in a debit balance which is subject to interest payments.  The net effect in this example would be to reduce and potentially erase the earnings on the High Synthetic position

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