Abstract:
An electronic market for trading of securities includes a plurality of client stations for entering quotes for securities and a server process. The market has a facility, which receives quotes from the clients, aggregates the quotes and causes a total of all aggregated quotes to be displayed for a plurality of price levels on the client systems. The market uses a graphical user that depicts aggregated quotes in an aggregate window, and a plurality of price levels of a product traded in the market. The market also includes processes to handle odd-lot processing and provides a central quote/order collector that interfaces to disparate order delivery systems to minimize dual liability of market makers.

Description:
BACKGROUND 
     This invention relates to trading systems particularly financial trading systems. 
     Electronic equity markets, such as The Nasdaq Stock Market® collect, aggregate, display pre-trade information to market participants. Electronic equity markets also provide trading platforms through which market participants may access liquidity indicated in the marketplace. In some types of markets customer orders are entered by broker/dealers or equivalents and traded against other orders or quotes that are displayed by market makers or electronic commerce networks (ECN&#39;s). Sometimes orders are for what is commonly referred to as an odd lot, e.g., an order that is not a multiple of 100 shares. 
     One type of trading platform is the Small Order Execution System (SOES SM ). The Small Order Execution System can be used to access, e.g., market makers quotes, via automatic execution if the order is for a public customer and meets a maximum order size requirement. Conventionally, in systems such as the Small Order Execution System (SOES SM ) odd lots are processed against only those market makers who are at the inside bid or offer, in round-robin fashion. An odd-lot execution does not decrement or decrease a market maker&#39;s quote by the amount of the execution. 
     SUMMARY 
     According to an aspect of the present invention, a A method for trading odd-lots of a security in an electronic market for trading securities includes determining whether an odd-lot exposure limit has been exceeded for a market participant and routing a received odd-lot order for execution or delivery to a market participant whose odd-lot exposure limit has not been exceeded and which is sufficient to satisfy execution of the order. 
     According to an additional aspect of the present invention, an electronic market for trading securities, includes an order execution/routing manager that executes non-directed orders against quoting market participant&#39;s quotes/orders based on a priority and a process to determine whether an order is a mixed order or an odd lot order. The market also includes an odd-lot execution process that executes the odd-lot portion of the mixed order or the odd-lot order. The odd-lot process includes a process to determine whether an odd-lot exposure limit has been exceeded for a market participant and a process to route a received odd-lot order for execution or delivery to a market participant whose odd-lot exposure limit has not been exceeded and which is sufficient to satisfy execution of the order. 
     According to an additional aspect of the present invention, a computer program product residing on a computer readable medium for trading securities in an electronic market, includes instructions for causing a computer to, determine whether a received order is a mixed order or an odd lot order and retrieve an odd-lot exposure limit for a next quoting market participant. The instructions determine whether the odd-lot exposure limit has been exceeded for a market participant, and routes a received odd-lot order for execution or delivery to a market participant whose odd-lot exposure limit has not been exceeded and which is sufficient to satisfy execution of the order. 
     One or more of the following advantages may be provided by one or more aspects of the present invention. 
     In general, a market maker can and will maintain different exposure limits for each security that it makes a market in. The exposure limit can be set by the market maker. The odd-lot execution manager does not execute an odd-lot order against a market maker unless the market maker had a sufficient exposure limit to fill the odd-lot order. Despite the potential for odd-lot processing in a security to suspend if no market maker establishes an exposure limit, it is likely that competitive forces to capture and service this segment of the market will yield swift and robust processing of odd-lot transactions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a market system. 
         FIG. 1A  is a diagram showing a format for quotes. 
         FIG. 2A  is a block diagram showing arrangement of an quote/order collector facility. 
         FIG. 2B  is a logic view of functions in the quote/order collector facility. 
         FIG. 3A  is a flow chart showing a quote/order manager. 
         FIG. 3B  is a flow chart showing a montage manager. 
         FIGS. 4A-4B  are flow charts of an execution/routing manager. 
         FIGS. 5A and 5B  are flow charts showing an odd lot execution manager. 
     
    
    
     DESCRIPTION 
     Referring to  FIG. 1 , an electronic market  10  is shown. The electronic market  10  includes client systems  12  that access a central quote/order collector facility  20 . The client systems  12  can be broker/dealer systems  12   a , electronic communication networks (ECN&#39;s)  12   b , market-marker systems  12   c , and other exchanges  12   d . The connections can use existing Nasdaq protocols such as SelectNet®, Small Order Execution System SM  (SOES SM ), and so forth. The client systems  12  include a processor, memory and a storage device, e.g., a client workstation or personal computer (all not shown) that can include a client process to enter quotes/orders into the electronic market system. The quote/order collector facility  20  causes the order execution or order delivery systems (e.g., SOES SM  and SelectNet®) to deliver executions or orders to a market that is coupled to a clearing system  16  and a reporting system  18 . It also causes delivery of executions or routing of orders to the ECN&#39;s  12   c , depending on the status of the ECN, and routing of orders or executions to other markets and exchanges  12   d . The quote/order collector facility  20  is comprised of one or preferably a plurality of server computers generally denoted as  22  including a processor  22   a , main memory  22   b  and storage  22   c . The storage system  22   c  includes quote/order collector process  25  that is executed in memory  22   b . In general, server  22  is a complex computer server, the details of which are not important to an understanding of the present invention. 
     The quote/order collector facility  25  collects pre-trade information in the form of quotes or orders. The distinction between a quote and an order depends on several factors. For example, each a market maker can send a proprietary quote i.e., a quote that represents its own trading interest or an agency quote that represents trading interest of a sponsored entity. If one proprietary quote is sent it could be considered one order. If one agency quote is sent it also could be considered one order. If an agency quote reflects an aggregation of more than one agency order, however, the aggregate agency order could be considered a quote. Entering quotes are limited to registered market makers  12   b  and ECNs  12   c  and possible UTP Exchanges  12   d . For any given stock, a registered market maker or ECN may directly enter a non-marketable order i.e., quote into the system  20  on behalf of its own account or for the account of a customer, or it may sponsor the direct entry of an order by its customer. All sponsored quotes are sent to the quote/order collector facility  20  under the name of the sponsoring market maker or ECN. Every registered market maker or ECN will be permitted to submit an unlimited number of non-marketable quotes to the system  20 . 
     As shown in  FIG. 1A , each quote  19  submitted to the system can include a display quote size  19   a , a reserve size  19   b  and an indication  19   c  (ATTR) of whether the quote size is attributable or non-attributable. Quote size  19   a  when attributable based on indicator  19   c , is directly attributable to the market maker or ECN, and is placed next to its unique market participant ID, and is displayed in a “current quote” montage. Quote size  19   b  when non-attributable is sized that the market maker or ECN wishes to display to the marketplace through an aggregate montage of the order display window. This quote size  19   a  is not attributable to the market maker or ECN until it is executed. Reserve size  19   b  is liquidity that is not displayed to the marketplace but that is immediately accessible through the quote/order collector facility  20 . In order to use reserve size  19   b , a market maker can be required to have a minimum amount displayed in the aggregate quote size  19   a  without or with attributable indicator  19   c  and negotiation quote with attributable indicator  19   c  asserted. 
     A broker/dealer can receive an order from a customer. The broker/dealer can send that order to the order collector facility  20  to be executed with quotes that are posted by electronic communication networks, market makers or other markets. In this embodiment, orders of broker/dealers are not posted as quotes. 
     Order Collector Facility 
     Referring to  FIG. 2A , the quote/order collector facility  20  receives quotes, liability orders, (non-liability orders) and directed orders from market participants. The quote/order collector facility  20  allows a quote/order to be displayed in the market, and also allows for marketable orders to be executed or routed to market participants. 
     The order quote collector facility  20  also includes an interface  21  that couples the order collector facility  20  to a plurality of order delivery systems. For example, the interface  21  can couple the order quote collector facility  20  to an order execution system, e.g., the Small Order Execution System SM  (SOES SM ) and to a negotiation system, e.g., SelectNet®. The interface  21  would provide access to information contained in order flow delivered via the delivery systems to a quote/order collection process  25  described in conjunction with  FIG. 2B . In general, the electrical and logical functions which comprise the interface  21  can be similar to the ones currently existing in the SOES SM /SelectNet® systems. The interface  21  or the process  25  would extract information from the quotes and make that information available to the quote order collector process  25 . The quote/order collector process  25  extracts information and process orders in a unified manner to allow the order collector system  20  to be a unifying point of collection of all orders which are sent to the market  10 . 
     The interface  21  can also be used to route executions of liability orders back to market participants whose quotes/orders were executed against and can deliver orders for negotiation against market participants whose quotes are selected for further negotiation via the SelectNet® system. 
     Referring to  FIG. 2B , the quote/order collector process (“OCP”)  25  is shown. The quote/order collector process  25  provides transmission of multiple orders or quotes at multiple price levels by Quoting Market Participants to a quotation manager  26   a . The quote/order manager  26   a  that provides a unified point of entry of quotes and orders from disparate delivery systems into the quote/order collector facility  20  to access quotes/orders displayed (as either attributable or non-attributable) in both the aggregate montage and current quote montage. The quote/order manager  26   a  manages multiple quotes/orders and quotes/orders at multiple price levels and uses a montage manager  26   b  to display (either in the Aggregate montage or in the current quote montage) the orders/quotes consistent with an order&#39;s/quote&#39;s parameters. The order collector process  25  also includes an internal execution process manager  26   c  to match off executions for quoting market participants at the best bid/offer. The order collector system  20  also includes an order routing/execution manager  26   d  provides a single point delivery of executions or routing of orders, which substantially eliminates potential for dual liability. That is, order collector process  25  will maintain the order routing and executions functionality available in the SOES SM  and SelectNet® systems. The order collector process  25  also includes a quote update manager  26   e , a lock/cross quote manager  26   f , and an odd lot execution manager  26   g.    
     Referring to  FIG. 3A , the order collector process  25  receives orders/quotes and time stamps  42  each order/quote upon receipt. This time stamp determines the order&#39;s/quote&#39;s ranking for interaction with incoming marketable orders. Quotes/orders are designated as either attributable or non-attributable, and could also have a reserve size discussed above. The order collector process  25  aggregates all of a Quoting Market Participant&#39;s attributable and non-attributable orders at a particular price level, and disseminates order/quotation information into the aggregate montage and/or the current quote montage, as will be discussed below. 
     The order entry process  25  determines  43  whether the received quote/order corresponds to a reserve quote. If the quote does not correspond to a reserve quote then the quote is a displayable quote that is attributable or non-attributable. The order entry process  25  compares  44  the received quotes/orders to existing quotes/orders to determine  46  whether the price of quotes/orders fall in existing quote/order price levels. Any number of quote/order price levels can be accommodated although, in this example, only three price levels will be displayable in the non-attributable i.e., aggregate montage. If the quote price is in a displayable price level it is a displayable quote eligible for automated execution. The order collector system  20  can be provided with more price level depth than the three levels, e.g., a depth of 20-25 levels although only a limited number, e.g., three would be displayed at any one time. 
     If the quote is within one of the pre-defined quote levels, the process  25  determines  48  new non-marketable quote/orders sizes by adding the quote/order size corresponding to the received quote/order to quote sizes at that price level already in the system  20 . The process  25  will cause the new non-marketable quote sizes to be displayed  50 . If the quote is not within one of the pre-defined quote levels, the process  25  stores  52  the quote at a new price level determines  54  if it is at a better price. If the quote is at a better price, the process  25  changes  56  current levels to cause a new price level for non-marketable quote sizes to be displayed  50 . 
     Referring to  FIG. 3B , the montage manager  26   b  of the quote/order collector process  25  determines  60  which price levels to display  60  and determines  61  if an order is a non-attributable order. If the order is non-attributable, the quote/order collector process  25  will store and sum  66  the quote with like quotes to produce an aggregated quote and display  68  the aggregate size of such orders in the aggregate montage when the orders fall within one of the three top price levels. For attributable orders, the aggregate size of such orders is displayed in the current quote montage once the order(s) at a particular price level becomes the particular quoting market participant&#39;s best attributable bid or offer in the current quote montage. This interest will also be aggregated and included in the aggregate montage if it is within the displayed price levels. Market makers and ECNs can have one MMID and possibly an agency MMID against which they can display attributable quotes. If a market maker has an agency quote, attributable orders will be displayed once the order or orders at a particular price level become the market participant&#39;s best agency quote. 
     For example, MMA sends system  20  five 1,000 shares attributable buy orders at $20 and two 1,000 share non-attributable buy orders at $20, for a total interest of 7,000 shares to buy at $20. At some point, the $20 price level becomes the best bid. In this example, if MMA is alone at the inside bid, system  20  will aggregate all of the orders in the system and display as follows: 7,000 shares in the Aggregate montage; 5,000 shares (the attributable portion) in the current quote montage next to MMA&#39;s MPID; and 2,000 (the non-attributable portion) in a “SIZE” MMID. 
     Quote/order collector system  20  provides several advantages to the market. One advantage is that it ensures compliance with the regulatory rules such as the SEC Order Handling Rules, and in particular the Limit Order Display Rule and SEC Firm Quote Rule. With system  20  it is less likely that a Quoting Market Participant, because of system delays and or/fast moving markets, will miss a market because the Quoting Market Participant is unable to quickly transmit to System  20  a revised quote (which may represent a limit order). 
     ECNs do not currently participate in the SOES SM  execution system because of the potential for dual liability and assuming proprietary positions. For example, if an ECN matches orders between two subscribers and contemporaneously receives an execution from SOES SM  against its quote, the ECN will be required to honor both the internal execution and the SOES SM  execution, thus taking on a proprietary position. This issue of liability does not arise in SelectNet® because that system delivers orders which can be declined if the ECN, after scanning its book, determines that the quote was taken out by an internal execution. An ECN cannot decline a SOES SM  execution because the system delivers an execution, as opposed to an order. 
     An ECN, like a market maker, can have the ability to give orders to the system  20 . If an internal subscriber wants to access an order in an ECN that is also being displayed in system  20 , the ECN can request a cancel before accomplishing the internal match. If the request to cancel is declined because the order was already executed against in system  20 , the ECN can decline the internal customer and avoid the potential for dual liability. 
     The OCF  20  will eliminate virtually all potential for double liability using the disparate execution and delivery systems that exist today because OCF  20  will serve as the single point of order entry and the single point of delivery of all Liability Orders (as well as Non-Liability Orders). 
     To access quotes in system  20 , therefore, order entry firms, market makers, ECNs, or UTP Exchanges, will enter either a directed or non-directed order into the OCF  25 . The order may be of any size. The order indicates whether it is a buy, sell, sell short, or sell short exempt. The order is either a priced order or a market order. The system  20  has a separate odd lot process described below. 
     Nondirected Orders 
     A market participant can immediately access the best prices in system  20  as displayed in the aggregate montage, by entering a non-directed order into the OCF  25 . A non-directed order is an order that is not sent/routed to a particular Quoting Market Participant. A non-directed order is designated as a market order or a marketable limit order and is considered a “Liability Order” and treated as such by the receiving market participant. Additionally, the order entry participant can obtain the status of the order and request a cancel of such order. Further, in some embodiments, the market  10  allows market participants that enter Non-Directed Orders three options as to how the order interacts with the quotes/orders in the system  20 . These choices are that the orders can execute against displayed contra side interest in strict price/time; or price/size/time; or price/time that accounts for ECN access fees. 
     Upon entry, the OCF  25  will ascertain what market participant is the next Quoting Market Participant in queue to receive an order based on the entering MP&#39;s ordering choice, and depending on how that receiving Quoting Market Participant participates in system  20  (i.e., automatic execution v. order delivery), the OCF  25  will either cause delivery of an execution (via SOES SM ) or delivery of a Liability Order (via SelectNet®). 
     Also in some embodiments, the market  10  can have a class of orders referred to as preferenced orders. A preferenced order is an order that is preference to a particular quoting market participant e.g., market maker or ECN. Preferenced Orders can be of two types price restrictions or no price restrictions. Preferenced Orders of either type are entered into the system  20  through the Non-Directed Order Process. The market participant entering the Preferenced Order designates the quoting market participant by its identification symbol (“MMID”). Preferenced Orders are processed in the same “queue” as Non-Directed Orders and are sent from the queue when the preferenced quoting market participant quote satisfies the order. 
     For example, if MMA and ECN 1  (non-automatic exception participant) are at the inside bid each displaying 1,000 shares at $20, and OE Firm A enters a market order to buy 1,000 shares, assuming that MMA is first in time priority, the OCF  25  will route the order into the SOES SM  and deliver an execution of 1,000shares to MMA via the SOES SM . If another market order to buy 1,000 shares is entered into the system, the OCF  25  will deliver a Liability Order to ECN 1 . If ECN 1  had opted to take automatic execution, the OCF would have delivered an execution to ECN 1  via the SOES SM . 
     Order Execution Manager 
     Referring to  FIG. 4A , an exemplary order execution/routing manager  26   d  executes non-directed orders against Quoting Market Participant&#39;s quotes/orders based on, e.g, price/time priority. As noted above, other priorities can be used and the execution/routing manager  26   d  would be so modified. Each quote/order when entered into the OCF  25  receives a time stamp. The order execution/routing manager  26   d  will deliver all orders at the best bid/best offer generally in strict time priority based on the time stamp of the order/quote, subject to the order execution choice preferencing features, and self matching feature, with the exception that order execution/routing manager  26   d  will first attempt to provide a match off of orders/quotes entered by a Quoting Market Participant if the participant is at the best bid/best offer by calling  74  an internal execution manager  26   c . Thus, the order execution/routing manager  26   d  will call the internal order execution manager  26   c  to try to match off a Quoting Market Participant&#39;s orders and quotes that are in the system if the participant is at the BBO and receives a market or marketable limit order on the other size of the market. 
     Generally, the order execution/routing manager  26   d  will attempt to execute  76  against all displayed size (attributable and non-attributable) at a particular price level for market participants such as market makers and ECN&#39;s. There does not need to be an interval delay between the delivery of executions against a market maker&#39;s quote (assuming the market maker has size to access) because all Quoting Market Participants may quote their actual size and may give multiple orders and price levels. As shown herein the market maker proprietary orders receive preference over agency orders. However, preference could be given to agency orders before market maker orders. 
     Once displayed size in system  20  is exhausted, the order execution/routing manager  26   d  will attempt to access the quotes of UTP Exchanges. After accessing the displayed size of Quoting Market Participants and UTP Exchanges  78 , order execution/routing manager  26   d  will attempt to execute  80  against the reserve size of Quoting Market Participants generally in price/time priority, subject to the exceptions noted above. 
     In an alternate embodiment, the order execution/routing manager  26   d  can distinguish between exchanges that support auto execution and exchanges that do not support auto execution giving preference for the former. Additionally, in such an embodiment, UTP exchanges can have reserve size and the system  20  can distinguish between exchanges that support auto execution and those ECN&#39;s, and then exchanges that do not support auto execution. 
     In another embodiment the order execution/routing manager  26   d  can first access quotes of market makers and auto-execution ECN&#39;s, next access quotes of market makers and ECN&#39;s for delivery of orders, then the reserve size of market makers and ECN&#39;s and UTP exchanges. Other arrangements priorities, etc. are possible taking into consideration how participants participate in the market  10 , choices of how orders interact in the market  10 , the system or customer choices. 
     Referring to  FIG. 4B , if the order is not filled  88 , the order execution/routing manager  26   d  will move  90  to the next price level, immediately in one embodiment, or in another embodiment, after a predefined delay, e.g., a 5 second interval delay  87  before attempting to execute an order at the new price level. The price-level interval delay will give market participants time to adjust their quotes and trading interests before the market moves precipitously through multiple price levels, which may occur when there is news, rumors, or significant market events. Thus, the price-level interval delay is a modest and reasonable attempt to limit volatility. 
     For non-directed orders that are mixed orders or odd lot orders the collector facility process  25  ( FIG. 2B ) calls an odd-lot execution manager  26   f.    
     Odd-Lot Processing 
     Referring to  FIG. 5A , an odd lot execution manager  26   g  is shown. The odd lot execution manager  26   g  accepts and executes orders that are for less than one normal unit of trading, i.e., odd-lot orders or orders less than one round lot (e.g., 100 shares for equities). The odd lot execution manager  26   g  is a separate mechanism for processing and executing these orders as distinct from normal units of trading. Odd lot execution manager  26   g  establishes  102  an odd-lot order routing parameter of a predetermined number of orders, e.g., one order per second, per firm. In one embodiment, the odd lot execution manager  26   g  accepts  104  an order per market participant that is at a rate set by the odd-lot order routing parameter  102 . The odd-lot execution manager  26   g  receives and holds 106 odd-lot orders in a separate file and automatically executes 110 such odd-lots against market makers, as described below. 
     For example, if a market participant enters a market order for 50 shares into the system, odd lot execution manager  26   g  will immediately and automatically call the odd lot process  110  to execute the order. Executions can be at the inside price against the market maker that is next in rotation, and which has an odd-lot exposure limit the market maker wishes to trade, via the odd-lot process and that can satisfy the order. Executions occur when the odd-lot order becomes marketable, i.e., when the best price in the system moves to the price of the odd-lot limit order. The odd-lot execution manager  26   g  will not decrease the market maker&#39;s displayed quote size, rather it will decrease the market maker&#39;s odd-lot exposure limit. 
     The odd-lot execution manager  26   g  accesses the “odd-lot exposure limit” parameter that is maintained for market makers. The odd-lot execution manager  26   g  also accesses and maintains a market maker interval delay between odd-lot executions against the same market maker. Odd-lots are processed in a round-robin fashion against a market maker even if it is not at the inside, odd-lots are processed only against those market makers who have an available odd-lot exposure limit. 
     Referring to  FIG. 5B , the odd-lot execution process  110  called by the odd-lot execution manager  26   g  is shown. The odd-lot execution manager  110  tracks (not shown) the odd-lot exposure limit that is set for each market maker in the particular security. In general, a market maker can and will maintain different exposure limits for each security that it makes a market in. In one embodiment, the exposure limit is set by the market maker. When a customer&#39;s odd-lot order is received by the odd-lot execution manager  26   g , the odd-lot order is executed automatically against the next available market maker. To determine the next available market maker, the process retrieves  112  the next market maker (as determined by a pointer  111   a  to a queue  191  entry, or equivalent techniques) and determines  112  whether the next market maker is beyond the interval delay and has a remaining odd-lot exposure limit that can satisfy the order. 
     The process  110  can access the queue structure  111  at a point determined by the pointer  111   a . The pointer  111   a  is updated during retrieving  120 . The queue  111  stores the exposure limit and interval delay parameters for the market makers, and so forth. The process  110  determines  112  if the exposure is exceeded or there is no exposure. If the exposure is exceeded or there is no exposure, then the next market marker exposure limit is retrieved and tested if any  113  are left. If none are left then the odd-lot processing is suspended  113   a . It remains suspended until a market maker refreshes its odd-lot exposure limit. 
     However, if the exposure is not exceeded then, when the odd-lot order becomes executable  114  (i.e., when the best price in the market moves to the price of the odd-lot limit order), the odd-lot order will execute  116  against the market maker (if not in the interval delay). Such odd-lot orders will execute  116  at the best price available in the market. Upon execution  116  the process will decrement the exposure limit for the market maker, update the time of execution and place the market maker at the bottom of the queue  111  (and is not in the interval delay). 
     Thus, the odd-lot execution manager  26   g  does not execute an odd-lot order against a market maker unless the market maker had a sufficient exposure limit to fill the odd-lot order. The odd-lot execution manager  26   g  decrements the exposure limit (not the quote or order sizes displayed in the quotation montage) by the size of the odd-lot order. When a market maker&#39;s odd-lot exposure is reduced to 0, the market maker is taken out of the odd-lot rotation unless and until the market maker sets a new exposure limit. 
     Despite the potential for odd-lot processing in a security to suspend if no market maker establishes an exposure limit, it is likely that competitive forces to capture and service this segment of the market will yield swift and robust processing of odd-lot transactions. Additionally, the use of the odd-lot process can result in such robust processing in other markets besides those that use market makers. 
     Thus, the order is executed in rotation against the market makers who have an exposure limit that would fill the odd-lot order. A market maker may, on a security-by-security basis, set an odd-lot exposure limit from 0 to a predefined number of shares, e.g., 999,999 shares. 
     For odd-lots that are part of a mixed lot, once the round-lot portion is executed, as discussed above the odd-lot portion will be executed at the round-lot price against the next market maker in rotation even if the round-lot price is no longer the best price in the market. Other arrangements are possible. 
     As mentioned, odd-lot executions will cause the odd-lot execution manager  26   g  to decrement the odd-lot exposure limit of a market maker. While, in some embodiments, the odd-lot execution manager will not decrement the market maker&#39;s displayed Quote/Order size upon execution of an odd-lot, in other embodiments the quote size can be decremented, when for example the number of odd lots executed equals one round lot. 
     After the odd-lot execution manager  26   g  has executed an odd-lot against a market maker, the system will not deliver another odd-lot order against the same market maker until a predetermined time period has elapsed from the time the last execution was delivered, as measured by the interval delay parameter as above. An exemplary value for this period of time is 5 seconds, but other time periods can be used. 
     Other embodiments are within the scope of the following claims.