What Is a Cancellation?

What Is a Cancellation?

4 Min.

Cancellation notices are promptly sent by brokers to their clients in case an error affects one of the clients' trades. Although automated trading systems have reduced errors, they still happen regularly.


Within the realm of brokerage services, the issuance of a cancellation notice stands as a pivotal procedure executed by brokers to alert their clients about the occurrence of an inaccurate trade, subsequently initiating its cancellation process.

In adherence to the highest echelons of industry standards, the meticulous upkeep of comprehensive records pertaining to every step undertaken in the process of rectifying mistaken trades stands as an imperative practice mandated for brokers.

Cancellations Explained

In the contemporary landscape of brokerage services, automation has significantly advanced, yet the persistence of erroneous trades remains a recurring phenomenon. Diverse factors contribute to this occurrence, spanning intricate technical glitches within automated trading systems to routine administrative oversights and human fallibility.

Upon the emergence of errors, brokers are mandated to promptly communicate the discrepancy to their clients and initiate an exhaustive documentation process to navigate toward its resolution. Should the brokerage firm bear the blame for the error, there exists the possibility of compensating the client for any adverse financial ramifications resulting from the mishap.

Throughout history, trading involved verbal and written exchanges, which often led to misinterpretations due to unclear verbal instructions or difficult to read handwritten notes. The advent of computerization has considerably mitigated these sources of errors, as instructions directly fed into computer systems are invariably executed with precision.

Nonetheless, an unintended byproduct of computerization lies in its capacity to exacerbate the impact of human errors when they materialize. As a case in point, a trader committing a "fat finger" mistake (inputting an erroneous price or quantity for a trade, such as inadvertently appending an extra zero to an order) faces limited corrective windows before the near-instantaneous computerized trading system enacts the error. Essentially, while previous generations of traders might have encountered a higher frequency of administrative blunders, their repercussions were conceivably less profound in contrast to the contemporary scenario.

Cancellation Example

Imagine a circumstance wherein a brokerage entity procures 500 shares of XYZ Corporation on behalf of its clientele. Regrettably, an administrative misstep surfaced as the floor broker erroneously submitted an order for 500 shares of ABC Corporation instead.

Upon detecting this error, the brokerage undertakes a series of corrective measures. Primarily, the client is promptly apprised of the error through a cancellation communication, delineating the nature of the misjudgment and affirming ongoing cancellation endeavors. Upon receiving client notification of an error, the brokerage procures the requested XYZ shares to rectify the issue for the client.

Should the valuation of XYZ Corporation's shares surge before the trade's modification, the brokerage could potentially find itself obligated to redress the client for the supplementary expenses incurred during the trade's execution.

SEC Regulations Governing Trade Accuracy

With the aim of risk reduction, the Securities and Exchange Commission (SEC) ratified protocols in 2009 devised to oversee the prevalence of flawed trade executions. These regulations empower exchanges to annul trades where the proposed price diverges by a specified proportion from the most recent prevailing market price of the relevant security. To accommodate the divergence in bid-ask spreads due to varying market capitalizations, distinct percentage thresholds were delineated by the SEC based on the security's share price.

Within standard trading hours, the SEC-mandated percentages stand at 10% for stocks under $25, 5% for stocks priced between $25 and $50, and 3% for stocks valued at $50 and above. Furthermore, these regulations dictate a swift review of erroneous trades within one hour from flagging. This entails the commencement of the review within 30 minutes of the trade's issuance, culminating in a conclusive review within the subsequent 30 minutes. For pre-market and after-hours trading, marked by reduced liquidity, the threshold for erroneous percentage deviations is doubled due to constrained market conditions.

Initiating the review process entails submitting the transaction's timing, security details, share quantity, transaction price, and transaction side (buy, sell, or both), along with elucidating the rationale for deeming the trade as erroneous to the exchange.


Cancellation notices are crucial for rectifying trade errors in brokerage services. Despite automation, inaccuracies persist due to glitches and human errors. Brokers promptly inform clients and document remedies, following strict standards. The SEC's regulations are pivotal, allowing trade cancellations for significant price deviations based on security value and trading hours. Tight review timeframes ensure a quick resolution, with added caution during low liquidity periods. This underscores the industry's commitment to precise brokerage services.

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Hexn operates under HEXN (CZ) s.r.o. and HEXN Markets LLC. HEXN (CZ) s.r.o. is incorporated in the Czech Republic with the company number 19300662, registered office at Cimburkova 916/8, Žižkov, Praha. HEXN (CZ) s.r.o. is registered as a virtual assets service provider (VASP). HEXN Markets LLC is incorporated in St. Vincent and Grenadines with the company number 2212 LLC 2022, registered office at Beachmont Business Centre, 379, Kingstown, Saint Vincent and the Grenadines