SNLN Highland iBoxx Senior Loan

HIGHLAND/iBOXX SENIOR LOAN ETF

(the "Fund")

Supplement dated April 10, 2020 to the Fund's Statement of Additional Information (the "SAI"),

dated October 31, 2019, as supplemented from time to time

This supplement provides new and additional information beyond that contained in the SAI and should be read in conjunction with the SAI. Capitalized terms and certain other terms used in this supplement, unless otherwise defined in this supplement, have the meanings assigned to them in the SAI.

Effective immediately, the following will replace the section entitled "Management of the Trust" including the headings "Qualifications of Trustees", "Trustees' Compensation", "Role of the Board of Trustees, Leadership Structure and Risk Oversight", "Share Ownership" and "Trustee Positions" beginning on page

17 of the SAI:

Role of the Board, Leadership Structure and Risk Oversight

The Role of the Board

The Board oversees the management and operations of the Trust. Like most RICs, the day-to-day management and operation of the Trust is performed by various service providers to the Trust, such as HCMFA, the Sub-Adviser, the Underwriter, administrator, sub-administrator, custodian, and the Transfer Agent, each of which is discussed in greater detail in this SAI. The Board has appointed senior employees of certain of these service providers as officers of the Trust, with responsibility to monitor and report to the Board on the Trust's operations. The Board receives regular reports from these officers and service providers regarding the Trust's operations. For example, the Treasurer provides reports as to financial reporting matters and investment personnel report on the performance of the Fund. The Board has appointed a Chief Compliance Officer who administers the Trust's compliance program and regularly reports to the Board as to compliance matters. Some of these reports are provided as part of formal in person Board meetings which are typically held quarterly, in person, and involve the Board's review of, among other items, recent Trust operations. The Board also periodically holds telephonic meetings as part of its review of the Trust's activities. From time to time one or more members of the Board may also meet with management in less formal settings, between scheduled Board meetings, to discuss various topics. In all cases, however, the role of the Board and of any individual Trustee is one of oversight and not of management of the day-to-day affairs of the Trust and its oversight role does not make the Board a guarantor of the Trust's investments, operations or activities.

Board Structure and Leadership

The Board has structured itself in a manner that it believes allows it to perform its oversight function effectively. The Board consists of four Trustees, three of whom are Independent Trustees. Mr. Powell serves as Chairman of the Board. The Trustees meet periodically throughout the year in person and by telephone to oversee the Trust's activities, review contractual arrangements with service providers for the Trust and review the Trust's performance. The Board conducts much of its work through certain standing Committees and the Audit and Qualified Legal Compliance Committee and the Governance and Compliance Committee are chaired by an Independent Trustee.

The Board has established an Audit and Qualified Legal Compliance Committee, a Governance and Compliance Committee and a Distribution and Alternatives Oversight Committee, each of which are discussed in greater detail below.

Audit and Qualified Legal Compliance Committee. The members of the Audit and Qualified Legal Compliance Committee are Dr. Froehlich and Messrs. Powell and Ward each of whom is independent for purposes of the 1940 Act. The Audit and Qualified Legal Compliance Committee is responsible for approving the Trust's independent accountants, reviewing with the Trust's independent accountants the plans and results of the audit engagement and the adequacy of the Trust's internal accounting controls, approving professional services provided by the Trust's independent accountants. The Audit and Qualified Legal Compliance Committee is charged with compliance with Rules 205.2(k) and 205.3(c) of Title 17 of the Code of Federal Regulations regarding alternative reporting procedures for attorneys representing the Trust who appear and practice before the SEC on behalf of the Trust. The Audit and Qualified Legal Compliance Committee is also responsible for reviewing and overseeing the valuation of debt and equity securities that are not publicly traded or for which current market values are not readily available pursuant to policies and procedures adopted by the Board. The Board and Audit and Qualified Legal Compliance Committee will use the services of one or more independent valuation firms to help them determine the fair value of these securities. In addition, each member of the Audit and Qualified Legal Compliance Committee meets the current independence and experience requirements of Rule 10A-3 under the Exchange Act.

The Audit and Qualified Legal Compliance Committee met nine times during the fiscal year ended June 30, 2019. Mr. Ward acts as the Chairman of the Audit and Qualified Legal Compliance Committee and as the audit committee financial expert.

The Governance and Compliance Committee. The Trust's Governance and Compliance Committee's function is to oversee and make recommendations to the full Board or the Independent Trustees, as applicable, with respect to the governance of the Trust, selection and nomination of Trustees, compensation of Trustees, and related

matters, as well as to oversee and assist Board oversight of the Trust's compliance with legal and regulatory requirements and to seek to address any potential conflicts of interest between the Trust and HCMFA in connection with any potential or existing litigation or other legal proceeding related to securities held by the Trust and the Adviser or another client of the Adviser. The Governance and Compliance Committee is also responsible for at least annually evaluating each Trustee and determining whether to recommend each Trustee's continued service in that capacity. The Governance and Compliance Committee will consider recommendations for Trustee nominees from shareholders sent to the Secretary of the Trust, 300 Crescent Court, Suite 700, Dallas, Texas 75201. A nomination submission must include all information relating to the recommended nominee that is required to be disclosed in solicitations or proxy statements for the election of Trustees, as well as information sufficient to evaluate the recommended nominee's ability to meet the responsibilities of a Trustee of the Trust. Nomination submissions must be accompanied by a written consent of the individual to stand for election if nominated by the Board and to serve if elected by the shareholders, and such additional information must be provided regarding the recommended nominee as reasonably requested by the Governance and Compliance Committee. The Governance and Compliance Committee is currently comprised of Dr. Froehlich and Messrs. Ward and Powell, each of whom is independent for purposes of the 1940 Act. Dr. Froehlich serves as the Chairman of the Governance and Compliance Committee. Prior to the February 28, 2019-March 1, 2019 Board Meeting, the Governance and Compliance Committee was divided into the Governance Committee and the Compliance Committee, each of which met one time during the fiscal year ended June 30, 2019.The Governance and Compliance Committee met two times during the fiscal year ended June 30, 2019.

The Distribution and Alternatives Oversight Committee. The members of the Distribution and Alternatives Oversight Committee are Dr. Froehlich, Messrs. Honis, Ward, and Powell. The Distribution and Alternatives Oversight Committee is responsible for reviewing arrangements with financial intermediaries who provide service to the Trust, including Trust payments to financial intermediaries, and for overseeing any funds that, in the Board's determination, employ alternative investment strategies.

Mr. Honis serves as Chairman of the Distribution and Alternatives Oversight Committee. Prior to the February 28, 2019-March 1, 2019 Board Meeting, the Distribution and Alternatives Oversight Committee was divided into the Distribution Oversight Committee and the Alternatives Oversight Committee, each of which met one time during the fiscal year ended June 30, 2019. The Distribution and Alternatives Oversight Committee met two times during the fiscal year ended June 30, 2019

The Board is led by Ethan Powell, who has served as the Chairman of the Board since December 2013. Under certain 1940 Act governance guidelines that apply to the Trust, the Independent Trustees will meet in executive session, at least quarterly. Under the Trust's governing documents, the Chairman of the Board is responsible for (a) presiding at board meetings, (b) calling special meetings on an as-needed basis, (c) execution and administration of Trust policies including (i) setting the agendas for board meetings and (ii) providing information to board members in advance of each board meeting and between board meetings. The Trust believes that the Chairman, and, as an entity, the full Board, provide effective leadership that is in the best interests of the Trust and each shareholder.

The Board periodically reviews its leadership structure, including the role of the Chairman. The Board also completes an annual self-assessment during which it reviews its leadership and Committee structure and considers whether its structure remains appropriate in light of the Trust's current operations. The Board believes that its leadership structure, including the current percentage of the Board who are Independent Trustees, is appropriate given its specific characteristics. These characteristics include: (i) the extent to which the work of the Board is conducted through the standing committees, and that the Audit and Qualified Legal Compliance Committee and the Governance and Compliance Committee meetings are chaired by an Independent Trustee; (ii) the extent to which the Independent Trustees meet as needed, together with their independent legal counsel, in the absence of members of management and members of the Board who are "interested persons" of the Trust; and (iii) Mr. Powell's previous positions with the Adviser and an affiliate of the Adviser and Mr. Honis' previous position with an affiliate of the Adviser, which enhance the Board's understanding of the operations of the Adviser.

Board Oversight of Risk Management

The Board's role is one of oversight, rather than active management. This oversight extends to the Trust's risk management processes. These processes are embedded in the responsibilities of officers of, and service providers to, the Trust. For example, HCMFA, the Sub-Adviser and other service providers to the Trust are primarily responsible