1 Cover page

Individual name: Thomas Seehusen
Individual CRD number: 6956945
Firm name: Advisory API Systems LLC
Firm CRD number: 330083
Firm address: 10667 Cranks Road, Culver City, CA 90230
Firm phone number: (310) 839-0358
Firm email address: [email protected]
Firm chief compliance officer: Thomas Seehusen

This brochure supplement provides information about Thomas Seehusen that supplements the Advisory API Systems LLC brochure. You should have received a copy of that brochure. Please contact Thomas Seehusen, the chief compliance officer of Advisory API Systems LLC, if you did not receive the brochure of Advisory API Systems LLC, or if you have any questions about the contents of this supplement.

Additional information about Thomas Seehusen is available on the Investment Adviser Public Disclosure website at www.adviserinfo.sec.gov, which displays registration information for both SEC-registered and state-registered investment advisers.

1.1 About this brochure supplement

Advisory API Systems LLC provides investment advice through a portfolio optimization application programming interface (API) to two categories of clients: (1) other registered investment advisers (“RIA Clients") in a business-to-business (B2B) capacity, and (2) individual members of the public (“Individual Clients") in a business-to-consumer (B2C) capacity. Although the firm delivers investment advice through an API rather than through direct personal interaction, Thomas Seehusen is the supervised person responsible for developing, validating, and overseeing the algorithms and methodology that generate the API’s investment recommendations. This brochure supplement is provided to give Clients information about his qualifications, background, and any disciplinary history that may be material to evaluating the firm’s services.

2 Educational background and business experience

2.1 Name

Thomas Seehusen

2.2 Year of birth

1960

2.3 Educational Background

1986 UCLA; Bachelor of Science in Physics
2014 University of Technology, Sydney; MBA in Finance

2.4 Business background

Thomas Seehusen has been an investment advisor representative since June 2018. Thomas Seehusen is managing member of Advisory API Systems LLC since January 2024. Prior to this, Thomas Seehusen was managing member of VIA LLC from 2018 to 2023. From 2014 to 2018, Thomas Seehusen was not employed in the securities industry.

Advisory API Systems LLC provides investment advice through a portfolio optimization application programming interface (API) to other registered investment advisers (“RIA Clients") and to individual members of the public (“Individual Clients"). Thomas Seehusen is responsible for developing and maintaining the API methodology, overseeing firm operations, and ensuring regulatory compliance.

2.5 Professional designations

Thomas Seehusen does not hold any professional designations that are required to be disclosed in this brochure supplement.

3 Disciplinary information

Thomas Seehusen is required by law in this brochure supplement to disclose any past legal or disciplinary events in which he was involved that are material to a client’s, or prospective client’s, evaluation of him. Thomas Seehusen has no applicable events to report under this section.

4 Other business activities

Thomas Seehusen is not currently engaged in any other business or occupation besides providing investment advice through Advisory API Systems LLC. Thomas Seehusen does not receive any compensation from any other business activity that provides a substantial source of income or involves a substantial amount of his time.

5 Additional compensation

Thomas Seehusen does not receive any economic benefit from any person or entity other than Advisory API Systems LLC in connection with the provision of investment advice to Clients. Compensation is derived from per-API-use fees charged to Clients as described in the firm’s Form ADV Part 2A brochure.

6 Supervision

Thomas Seehusen is the sole owner and managing member of Advisory API Systems LLC. In this capacity, Thomas Seehusen is responsible for overseeing all recommendations and advice rendered through the firm’s API. Every effort is made to ensure compliance with law and the firm’s fiduciary duty to its Clients to act in their interest and to avoid any conflicts of interest.

The firm’s API generates investment recommendations using mathematical algorithms based on modern portfolio theory. Thomas Seehusen is responsible for the development, validation, and ongoing monitoring of these algorithms to ensure they produce appropriate recommendations. This includes:

• Developing and maintaining the mathematical methodology underlying the API;

• Validating that algorithm outputs are consistent with the intended methodology;

• Monitoring for errors or anomalies in API outputs;

• Updating the methodology as appropriate based on academic research, regulatory changes, or other factors;

• Ensuring that all required disclosures are provided to Clients.

As the sole supervised person of the firm, Thomas Seehusen’s activities are not supervised by another person within the firm. However, the firm maintains written compliance policies and procedures, and Thomas Seehusen conducts periodic reviews to ensure adherence to applicable laws and regulations.

The person responsible for supervising Thomas Seehusen’s advisory activities is Thomas Seehusen, Managing Member and Chief Compliance Officer. He can be reached at (310) 839-0358 or [email protected].

7 Requirements for state-registered advisers

7.1 Events in addition to those required to be disclosed in section 3 of Form ADV Part 2B

Thomas Seehusen has not been involved in any of the events listed below and therefore has nothing to disclose in this regard.

7.1.1 An award or otherwise being found liable in an arbitration claim alleging damages in excess of $2,500, involving any of the following:

(a) an investment or an investment-related business or activity;

(b) fraud, false statement(s), or omissions;

(c) theft, embezzlement, or other wrongful taking of property;

(d) bribery, forgery, counterfeiting, or extortion; or

(e) dishonest, unfair, or unethical practices.

7.1.2 An award or otherwise being found liable in a civil, self-regulatory organization, or administrative proceeding involving any of the following:

(a) an investment or an investment-related business or activity;

(b) fraud, false statement(s), or omissions;

(c) theft, embezzlement, or other wrongful taking of property;

(d) bribery, forgery, counterfeiting, or extortion; or

(e) dishonest, unfair, or unethical practices.

7.2 Bankruptcy

Thomas Seehusen has not been the subject of a bankruptcy petition within the past 10 years. A bankruptcy petition was filed in 1994 and fully discharged; it is outside the disclosure period required by Form ADV Part 2B.