OMS / EMS Tool
Reconciliation Break Simulator
Investment Education, Research & Tools for Smarter Decisions.
Enter position snapshots from your OMS and broker, identify breaks, classify each by type (quantity, price, timing), and generate a resolution checklist. Uses synthetic or user-entered data only.
Direct Answer
A reconciliation break simulator compares position snapshots from an OMS and a broker, identifies breaks between them, classifies each by type, quantity, price, or timing, and generates a resolution checklist. Enter up to six position rows of synthetic or your own data to see how the classification works. Practicing on simulated breaks builds the pattern recognition needed to resolve real reconciliation breaks quickly.
Tool
Enter up to 6 position rows. For each symbol, enter the OMS quantity, broker quantity, OMS closing price, broker closing price, and whether a recent fill is pending (helps classify timing breaks).
Uses synthetic or user-entered data only.
How to use this tool
Enter position data for up to 5 symbols. For each symbol, provide the quantity and closing price from your OMS, and the quantity and closing price as reported by your broker or custodian. Check the "Recent fill pending" box if there was unacknowledged order activity in that symbol near the snapshot time, this helps the tool classify a quantity difference as a possible timing break rather than a confirmed error.
Click "Run Reconciliation" to see a comparison table showing breaks, their types, their market value impact (using the OMS closing price), and a classification: Quantity Break (different shares), Price Break (different prices, same shares), Timing Candidate (quantity differs but recent fill pending), or Match (fully reconciled).
The resolution checklist at the bottom of the results provides action items specific to each break type, what to investigate, who to contact, and what records to retain.
Understanding the outputs
A Quantity Break means the OMS and broker report different share counts for the same symbol. This is the most urgent break type. If no recent fill is pending, the discrepancy is likely a missing fill, a failed settlement, or a booking error on one side. The market value impact shown is the OMS quantity difference multiplied by the OMS closing price, a rough estimate of the position value at stake.
A Price Break means the share counts agree but the OMS and broker applied different closing prices. This affects NAV and P&L calculations but not risk limits. Common causes: different data vendors for closing prices, different handling of after-hours trades, or different pricing methodologies for illiquid names. Price breaks must be documented and agreed between the OMS and custodian to produce a consistent NAV.
A Timing Candidate is a quantity difference associated with a recent pending fill. This is the most likely self-resolving break type, the fill may be in-flight between the broker receiving it and the OMS processing the execution report. If it persists in the next reconciliation cycle after the fill should have been processed, it escalates to a confirmed Quantity Break.
A Match means both quantity and price are identical in the OMS and broker snapshots. No action is required for matched positions.
Assumptions and limitations
- This tool performs a simplified single-account, single-snapshot comparison. Production reconciliation systems compare multiple accounts, handle multiple snapshot timestamps, apply corporate action calendars, and manage break aging across cycles.
- Market value impact is estimated using the OMS closing price, not the broker's. In a real break, the market value impact may differ depending on which price the firm's NAV methodology treats as authoritative.
- The "Recent fill pending" checkbox is a manual indicator, a production system determines this automatically by checking open order status and fill receipt timestamps against the snapshot timestamp.
- This tool does not model cash reconciliation, settlement breaks, or multi-day break aging. See the End-of-Day Reconciliation guide for the full break management framework.
Frequently Asked Questions
What does "market value impact" mean in the results?
Market value impact is the quantity difference multiplied by the OMS closing price. It gives a rough estimate of how much money is at stake if the break represents a real position error, if the OMS overstates a position, it may make trading decisions believing it has more exposure than it actually has, by approximately this amount.
Why does a price break not affect risk limits?
Risk limits are typically set in share quantities, not dollar values. A price break means both systems agree on how many shares are held but disagree on what price to apply. The quantity-based risk limit is unaffected. The dollar-based risk metric (e.g., 5% of NAV in a single name) may be affected if the price difference is material.
What if the OMS quantity is lower than the broker quantity?
If the broker shows more shares than the OMS, the OMS is understating its position. This is typically caused by a fill that the broker received and processed but the OMS never recorded, a missing execution report. The resolution is to identify the missing fill, book it in the OMS, and update the position. The checklist will reflect this direction.
Can I export the results from this tool?
This tool does not have a native export function. To save the results, use your browser's print function (Ctrl/Cmd+P) and save as PDF, or manually copy the break table and checklist into your operations documentation. A production reconciliation system would output structured files (CSV, XML) directly to your break management system.
What should I do if a timing break doesn't resolve in the next cycle?
If a position marked as "timing candidate" is still a break in the next reconciliation cycle, even though sufficient time has passed for the pending fill to be processed, it should be reclassified as a confirmed quantity break and escalated. The next steps are to query the EMS directly for the fill execution report status, check the FIX session logs for any dropped messages, and contact the broker's trade support to verify what they show for the order.
What data does the simulator need for each position row?
A matched pair of figures for the same instrument, one from the order management system and one from the broker, covering quantity and price. The comparison is between two views of the same position, so a row missing one side is treated as a presence break rather than a quantity difference. Using synthetic values is the intended default, and entering real positions works equally well since the comparison runs in the browser and nothing is transmitted.
How does the simulator distinguish a timing break from a genuine one?
A timing break has the signature of a trade recorded on one side and not yet on the other, so the difference matches a plausible recent execution rather than an arbitrary amount. The simulator classifies by that pattern. In practice the confirmation is temporal: a timing break resolves on the next comparison cycle without any intervention, and one that persists across cycles is not a timing break regardless of how it initially looked.
Why does the simulator separate quantity breaks from price breaks?
They have different causes and different consequences. A quantity difference means the two systems disagree about how much is held, which affects exposure, risk limits, and any order sized from the position. A price difference usually means a valuation source or a timing difference and affects reported value without changing exposure. Investigating them together tends to produce a single mixed queue in which the urgent cases are not visibly urgent.
How does practicing here transfer to a real reconciliation process?
What transfers is the classification habit: identifying the break type before investigating, and letting the type determine the first check rather than starting from the largest number. What does not transfer is everything a real process contends with, including instrument mapping differences between systems, corporate actions, multi-account aggregation, settlement timing, and the volume of rows a production comparison produces. The simulator builds the reasoning step, not the operational one.
References
- Intraday Position Reconciliation: Full guide on the reconciliation cycle, break detection, and escalation procedures.
- End-of-Day Reconciliation and Break Management: EOD process, break classification tiers, and settlement break handling.
- SIFMA Operations Best Practices: Industry guidance on reconciliation standards.
Disclaimer
This tool is for educational purposes only. It uses user-entered or synthetic data exclusively. Results are illustrative and do not constitute financial, compliance, or operational advice. Always verify breaks using your firm's official reconciliation system and procedures.