U.S. option exchanges have rules that distinguish between orders originating from public customers (i.e., not broker-dealers) whose trading behavior is deemed to be “Professional” (i.e., persons or entities trading in a manner more akin to a market maker than to a typical customer) and those whose trading behavior is not.  In accordance with these rules, any customer that is not a broker-dealer and averages more than 390 option orders (for its own beneficial account(s)) per day in U.S.-listed options in at least one month of a calendar quarter will be classified as Professional.

Orders submitted on behalf of Professional customers are treated the same as those of broker-dealers for purposes of execution priority and fees. 

Brokers are required to conduct a review on at least a quarterly basis to identify those customers who have exceeded the 390 order threshold for any month in that quarter, and such customers will be designated as Professional as of the next calendar quarter.

Order Counting

The definition of an order for these purposes varies slightly across exchanges, and customers seeking specific options counting rules (especially in connection with the use of algorithmic order types that might result in placing orders on both sides of the market under certain circumstances) should review the relevant exchange rulebooks and guidance. However, for purposes of options order counting, an order is generally defined as:

• A single order;
• A complex order of 8 or fewer option legs;
• Each option leg of a complex order of 9 or more option legs; or
• A parent order, even if that order is broken into multiple child orders on the same side/series by a broker for execution or routing purposes (except in connection with orders pegged to the NBBO, as discussed below). 

A customer-initiated cancelation and replacement (by any method, including, for example, as a result of Scale orders) of a parent order counts as a new order(s) according to the logic above (e.g., a cancel/replace of a single-leg order counts as one new order, whereas a cancel/replace of a nine-option-leg order counts as nine new orders). 

Orders Pegged to the NBBO/BBO

Note that for customers who use options orders pegged to the NBBO or BBO (such as, for example, relative orders or Pegged Volatility orders, or other parent order types designed to move with the NBBO/BBO), each cancel/replace of a child order based on a change in the NBBO/BBO constitutes an additional new order. Customers resting pegged orders in IBUSOPT for participation in RFQ auctions should also be aware that a pegged order will be treated as canceled and replaced each time such order participates in an RFQ auction in IBKR’s system (whether or not such order becomes an initiating order in an on-exchange auction). 

Account Aggregation

In calculating order totals, brokers must aggregate the options orders of all beneficially-owned accounts of the customer. IBKR aggregates options orders from an individual’s or entity’s account with those of related joint accounts, trust accounts, and organizational accounts.

Customers will be notified by IBKR upon a status change from a retail customer to a Professional customer. In addition, IBKR’s smart order router is designed to take exchange fees (including differences between professional and non-professional customer fees) into consideration when making routing decisions.

For additional details, please see the following links:

CBOE Regulatory Circular RG16-064

ISE 2014 RIC and 2016 RIC

NYSE AMEX 10-29

Rule 611, which is the Trade Through Exemption of SEC Regulation NMS, is very lengthy to cover in detail.  Parties interested in reading the rule in its entirely should type "SEC Rule 611" into an internet search engine.  This is the portion of the document that is pertinent to IB traders, in a nutshell:

Typically the trades involved are a multi-component trade involving orders for a security and a related derivative, or, in the alternative, orders for related securities, that are executed at or near the same time.  The SIA (Securities Industry Association) notes that the economics of a contingent trade are based on the relationship between the prices of the security and the related derivative or security, and that the execution of one order is contingent upon the execution of the other order. 

The bottom line is that when a trade is ruled R6 the SEC has granted a trade-through exemption.  This means that these execution reports do not affect the resting orders in-between the market at the time, and the R6 execution.  For example, the real market is quoting 10.50 at 10.51, and an execution is reported at 10.90.  This execution was given an R6 exemption.  A sell limit order at 10.75, an an example, would not be executed because the 10.90 execution was given an R6 status. 

Multiple accounts maintained in the same name and taxpayer ID number are grouped for purposes of applying the maximum per client protection limits of $500,000 by SIPC and $29.5 million under Lloyd’s supplementary protection. However, if you hold accounts with IBKR in separate capacities (for example, an account in your name, a trust account of which you are the trustee or a beneficiary, or a joint account), then each account would be protected by SIPC and the supplementary protection up to the stated limits.

Links:

Account Protection

SIPC

Regulation SHO, adopted by the SEC in January 2005, sets forth the regulatory framework governing short sales.  Two key provisions, intended to address problems associated with persistent fails to deliver and potentially abusive naked short selling, involve locate and close-out requirements.

Under the locate requirement, a broker-dealer must have reasonable grounds to believe that the security can be borrowed so that it can be delivered on the delivery due date before effecting a short sale order.  

The close-out requirement requires that the clearing broker take immediate action to close out a fail to deliver position in a threshold security that has persisted for 13 consecutive settlement days by purchasing securities of like kind and quantity. Until the position is closed out, the broker may not effect further short sales in that threshold security without borrowing or entering into a bona fide agreement to borrow the security (known as the "pre-borrowing" requirement)

IMPORTANT NOTE:

In October 2008, the SEC amended Regulation SHO with temporary Rule 204T (in place until July 31, 2009) which requires that any broker having a fail to deliver position at NSCC on the settlement date immediately borrow or purchase securities to close out the amount of the fail to deliver position by no later than the beginning of regular trading hours on the following settlement date (the “Close-Out Date”). This close-out requirement requires that the broker take affirmative action to purchase or borrow securities and not offset the fail to deliver position with shares it will receive on the Close-Out Date. Rule 204T applies to all securities not just threshold securities.