13D Filing: Highland Capital Management and Rait Financial Trust (RAS)

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE
13D/A

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED

PURSUANT TO RULE 13d-2(a)

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 6)

RAIT
FINANCIAL TRUST

(Name of Issuer)

Common Shares
of Beneficial Interest, $.03 par value per share

(Title of Class of Securities)

749227609

(CUSIP Number)

Thomas Surgent, Chief Compliance Officer

Highland Capital Management, L.P.

300 Crescent Court, Suite 700

Dallas, TX 75201

(Name,
Address and Telephone Number of Person Authorized to Receive Notices and Communications)

May 25, 2017

(Date of Event Which Requires Filing of this Statement)

If the filing
person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box.  ☐

SCHEDULE 13D

This Amendment No. 6 (this Amendment) is being filed on behalf of Highland Global Allocation Fund, a series of Highland Funds
II, a Massachusetts business trust (the Global Fund), Highland Small-Cap Equity Fund, a series of Highland Funds II, a Massachusetts business trust (the
Small-Cap Fund), Highland Capital Management Fund Advisors, L.P., a Delaware limited partnership (Highland Fund Advisors), Strand Advisors XVI, Inc., a Delaware corporation
(Strand XVI), NexPoint Real Estate Strategies Fund, a Delaware statutory trust (NRESF), NexPoint Advisors, L.P., a Delaware limited partnership (NexPoint Advisors), NexPoint Advisors GP, LLC, a Delaware limited
liability company (NexPoint Advisors GP), Highland Select Equity Master Fund, L.P., a Bermuda limited partnership (Select Fund), Highland Select Equity Fund GP, L.P., a Delaware limited partnership (Select GP),
Highland Select Equity GP, LLC, a Delaware limited liability company (Select LLC), Highland Capital Management, L.P., a Delaware limited partnership (Highland Capital), Strand Advisors, Inc., a Delaware corporation
(Strand), NexPoint Real Estate Advisors, L.P., a Delaware limited partnership (NRE Advisors), NexPoint Real Estate Advisors GP, LLC, a Delaware limited liability company (NRE Advisors GP), James D. Dondero, Matt
McGraner, Nancy Jo Kuenstner, John M. Pons, Andrew C. Richardson and Edward S. Friedman (collectively, the Reporting Persons), and amends the Schedule 13D originally filed on October 7, 2016, as amended by Amendment No. 1 to
the Statement on Schedule 13D filed on November 10, 2016, Amendment No. 2 to the Statement on Schedule 13D filed on December 5, 2016, Amendment No. 3 to the Statement on Schedule 13D filed on December 22, 2016, Amendment
No. 4 to the Statement on Schedule 13D filed on February 8, 2017, and Amendment No. 5 to the Statement on Schedule 13D filed on February 24, 2017 (as so amended, the Statement). The principal executive offices of the
Issuer are located at Two Logan Square, 100 N. 18^th Street, 23^rd Floor, Philadelphia, Pennsylvania 19103.

This Amendment No. 6 to Schedule 13D amends and supplements the Statement as follows. Except as provided herein, this Amendment
No. 6 does not modify any of the information previously reported on such Statement, including any amendment thereto.

Item 2 is hereby amended to add the following:

In connection with the execution of the Cooperation Agreement (as defined in Item 4 below) by the Investor Group (as defined in Item 4 below),
the Reporting Persons will no longer all be members of a Section 13(d) group and NRE Advisors, NRE Advisors GP, Ms. Kuenstner, Mr. Pons, Mr. Richardson and Mr. Friedman will cease to be Reporting Persons immediately after the
filing of this Amendment No. 6. The remaining Reporting Persons will continue filing reports as a group with respect to their beneficial ownership of securities of the Issuer to the extent required by applicable law and expect to continue
filing reports on Schedule 13G rather than Schedule 13D as they no longer hold securities of the Issuer for the purpose of, or with the effect of, changing or influencing the control of the Issuer, or in connection with or as a participant in any
transaction having that purpose or effect.

Item 4 is hereby amended to add the following:

On May 25, 2017, the Global Fund, Small-Cap Fund, Highland Fund Advisors, Strand XVI, NRESF,
NexPoint Advisors, NexPoint Advisors GP, Select Fund, Select GP, Select LLC, Highland Capital, Strand, HCRE Partners, LLC, NRE Advisors, NRE Advisors GP and Messrs. Dondero, McGraner and Friedman (each, individually, an Investor and
collectively, the Investor Group) entered into an agreement with the Issuer (the Cooperation Agreement).

Pursuant
to the Cooperation Agreement, the Investor Group has agreed to terminate its pending proxy contest against the Issuer and withdraw the notice of nomination submitted by the Select Fund proposing to seek the election of five candidates to the
Issuers Board of Trustees (the Board) at the Issuers 2017 Annual Meeting of Shareholders (the 2017 Annual Meeting).

Pursuant to the Cooperation Agreement, the Issuer has agreed that (i) following the certification of the vote of the Issuers
shareholders at the 2017 Annual Meeting, but no later than forty-five (45) calendar days from the date of execution of the Cooperation Agreement, the Board shall appoint either Nancy Jo Kuenstner or Andrew C. Richardson to its membership (the
New Trustee) to serve on the Board until the 2018 Annual Meeting of Shareholders (the 2018 Annual Meeting), (ii) within one hundred twenty (120) calendar days from the execution of the Cooperation Agreement, the Board
shall appoint a new trustee (the Second New Trustee) who shall not be an Affiliate or Associate (as such terms are defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended) of the

Investor Group (or a previous member of a Schedule 13D group with any member of the Investor Group) to serve on the Board until the 2018 Annual Meeting, provided that the Investor Group will have
one veto right with respect to the person chosen by the Board to serve as the Second New Trustee, (iii) during the Cooperation Period (as defined below), no less frequently than once every sixty (60) days, one or more members of the
Issuers management shall use its commercially reasonable efforts to schedule a telephonic meeting with a representative of the Investor Group to discuss information regarding the Issuer that the Issuer has, prior to such meeting, publicly
disclosed, and (iv) the Issuer will reimburse the Investor Group $250,000 for its out-of-pocket expenses, including legal fees and expenses, as actually incurred by
the Investor Group in connection with the matters related to the 2017 Annual Meeting, the filing of a Schedule 13D amendment in connection with the 2017 Annual Meeting and the negotiation and execution of the Cooperation Agreement.

Under the terms of the Cooperation Agreement, the Investor Group has agreed to certain standstill provisions with respect to the Investor
Groups actions with regard to the Issuer and the Issuers Common Shares, 7.75% Series A cumulative redeemable preferred shares, liquidation preference $25.00 per share, $0.01 par value per share, 8.375% Series B cumulative redeemable
preferred shares, liquidation preference $25.00 per share, $0.01 par value per share, and 8.875% Series C cumulative redeemable preferred shares, liquidation preference $25.00 per share, $0.01 par value per share. A majority of the standstill
provisions would be in effect for a standstill period commencing on the date of the Cooperation Agreement and ending two years from the date of the Cooperation Agreement. The other standstill provisions would be in effect for a
cooperation period that commenced on the date of the Cooperation Agreement and ends at 11:59 p.m. Eastern Time on the date of the certification of the vote of shareholders at the 2018 Annual Meeting (the Cooperation Period).

Pursuant to the Cooperation Agreement, each of the Investors has agreed, at each annual and special meeting of shareholders held prior to
the expiration of the Cooperation Period, to (A) appear, in person or by execution of the Companys proxy card, at such shareholders meeting or otherwise cause all Common Shares beneficially owned by each Investor and their
respective Affiliates and Associates to be counted as present thereat for purposes of establishing a quorum; (B) vote, or cause to be voted, all Common Shares beneficially owned by each Investor and their respective Affiliates and Associates on
the Companys proxy card or voting instruction form (1) in favor of each of the nominees for election as trustees nominated by the Board and recommended by the Board (and not in favor of any other nominees to serve on the Board), and
(2) in accordance with the Boards recommendations with respect to each of the proposals listed on the Companys proxy card or voting instruction form as identified in the Companys definitive proxy statement and any supplements
thereto, including in favor of all matters recommended by the Board for shareholder approval and against all matters which the Board recommends against shareholder approval; provided however that, in connection with any matter (other than the
election of nominees to the Board) to be voted upon by the Companys shareholders, after the certification of the vote of the Companys shareholders at the 2017 Annual Meeting, to the extent that the recommendation of Institutional
Shareholder Services Inc. (ISS) differs from the Boards recommendation with respect to such matter, the Investors may vote on the Companys proxy card or voting instruction form in accordance with the recommendation of ISS;
and (C) not execute any proxy card or voting instruction form in respect of such shareholders meeting other than the proxy card and related voting instruction form being solicited by or on behalf of the Company or the Board.

Pursuant to the Cooperation Agreement, each of the Investors has agreed, in connection with any action by written consent that is sought to be
taken by any party other than the Company or the Board prior to the expiration of the Cooperation Period, not to vote and to take all necessary action, including, without limitation, the execution and completion of any consent revocation card
solicited by the Company or the Board, in accordance with the recommendation of the Board, to cause not to be voted, any of the Common Shares beneficially owned by each Investor and/or their respective Affiliates and Associates on any consent card
related to or affecting the removal, replacement or election of Board members and solicited by any party, other than the Company or the Board.

Pursuant to the Cooperation Agreement, each of the Investors has agreed, in connection with any demand by a shareholder of the Company that
the Company call a special meeting of shareholders made prior to the expiration of the Cooperation Period, not to vote and to take all necessary action, including, but not limited to, the execution and completion of any consent revocation card
solicited by the Company or the Board in accordance with the recommendation of the Board, to cause not to be voted, any of the Common Shares beneficially owned by each Investor and/or their respective Affiliates and Associates for any special
meeting demand proposed or sought to be made by any party.

The Company and the Investor Group have also agreed to certain mutual non-disparagement and mutual release of claims provisions.

The Cooperation Agreement is attached
as Exhibit 99.8 hereto and is incorporated herein by reference. The foregoing description of the Cooperation Agreement is qualified in its entirety by reference to the full text of the Cooperation Agreement.

Item 5 is hereby amended and restated in its
entirety to read as follows:

The aggregate percentage of Common Shares reported owned by each person named herein is based upon
92,691,743 Common Shares outstanding as of May 8, 2017, which is the total number of Common Shares outstanding as reported in the Issuers Proxy Statement filed with the Securities and Exchange Commission on May 15, 2017.

(a) (b)

1. Global Fund

(a)    As of the close of business on May 26, 2017, Global Fund beneficially owned 2,219,361 Common Shares.

Percentage: Approximately 2.4%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,219,361

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,219,361

2. Small-Cap Fund

(a)    As of the close of business on May 26, 2017, Small-Cap Fund
beneficially owned 613,889 Common Shares.

Percentage: Approximately 0.7%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 613,889

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 613,889

3. Highland Fund Advisors

(a)    As of the close of business on May 26, 2017, Highland Fund Advisors, as the investment advisor to Global Fund
and Small-Cap Fund, may be deemed the beneficial owner of the 2,833,250 Common Shares held by Global Fund and Small-Cap Fund.

Percentage: Approximately 3.1%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,833,250

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,833,250

4. Strand XVI

(a)    As of
the close of business on May 26, 2017, Strand XVI, as the general partner of Highland Fund Advisors, the investment advisor to Global Fund and Small-Cap Fund., may be deemed the beneficial owner of the
2,833,250 Common Shares held by Global Fund and Small-Cap Fund.

Percentage: Approximately 3.1%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,833,250

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,833,250

5. NRESF

(a)    As of the
close of business on May 26, 2017, NRESF beneficially owned 117,040 Common Shares.

Percentage: Approximately 0.1%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 117,040

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 117,040

6. NexPoint Advisors

(a)    As of the close of business on May 26, 2017, NexPoint Advisors, as the investment advisor to NRESF, may be
deemed the beneficial owner of the 117,040 Common Shares held by NRESF.

Percentage: Approximately 0.1%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 117,040

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 117,040

7. NexPoint Advisors GP

(a)    As of the close of business on May 26, 2017, NexPoint Advisors GP, as the general partner of NexPoint Advisors,
the investment advisor to NRESF, may be deemed the beneficial owner of the 117,040 Common Shares held by NRESF.

Percentage: Approximately
0.1%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 117,040

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 117,040

8. Select Fund

(a)    As of
the close of business on May 26, 2017, Select Fund beneficially owned 2,332,087 Common Shares.

Percentage: Approximately 2.5%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,332,087

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,332,087

9. Select GP

(a)    As of
the close of business on May 26, 2017, Select GP, as the general partner of the Select Fund, may be deemed the beneficial owner of 2,332,087 Common Shares held by Select Fund.

Percentage: Approximately 2.5%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,332,087

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,332,087

10. Select LLC

(a)    As of
the close of business on May 26, 2017, Select LLC, as the general partner of the Select GP, the general partner of Select Fund, may be deemed the beneficial owner of 2,332,087 Common Shares held by Select Fund.

Percentage: Approximately 2.5%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,332,087

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,332,087

11. Highland Capital

(a)    As of the close of business on May 26, 2017, Highland Capital, as the sole member of Select LLC, the general
partner of the Select GP, which is the general partner of Select Fund, may be deemed the beneficial owner of 2,332,087 Common Shares held by Select Fund.

Percentage: Approximately 2.5%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,332,087

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,332,087

12. Strand

(a)    As of the
close of business on May 26, 2017, Strand, as the general partner of Highland Capital, the sole member of Select LLC, which is the general partner of the Select GP, which is the general partner of Select Fund, may be deemed the beneficial owner
of 2,332,087 Common Shares held by Select Fund.

Percentage: Approximately 2.5%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 2,332,087

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 2,332,087

13. Mr. Dondero

(a)    As of the close of business on May 26, 2017, Mr. Dondero, who is the president of NexPoint Advisors GP
(the general partner of the NRESFs advisor) and Strand (the general partner of the sole member of the general partner of Select Funds general partner) and ultimately controls Strand XVI (the general partner of the advisor to Global Fund
and Small Cap Fund) and NexPoint Advisors GP, may be deemed the beneficial owner of 5,282,377 Common Shares held by Global Fund, Small-Cap Fund, NRESF and Select Fund.

Percentage: Approximately 5.7%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 5,282,377

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 5,282,377

14. NRE Advisors, NRE Advisors GP, Ms. Kuenstner, Mr. Pons and Mr. Richardson

(a)    As of the close of business on May 26, 2017, none of NRE Advisors, NRE Advisors GP, Ms. Kuenstner,
Mr. Pons and Mr. Richardson beneficially owned any Common Shares.

Percentage: Approximately 0.0%

(b)    i. Sole power to vote or direct vote: 0

ii. Shared power to vote or direct vote: 0

iii. Sole power to dispose or direct the disposition: 0

iv. Shared power to dispose or direct the disposition: 0

15. Mr. McGraner

(a) As of the close of
business on May 26, 2017, Mr. McGraner beneficially owned 3,000 Common Shares.

Percentage: Less than 0.1%

(b)    i. Sole power to vote or direct vote: 3,000

ii. Shared power to vote or direct vote: 0

iii. Sole power to dispose or direct the disposition: 3,000

iv. Shared power to dispose or direct the disposition: 0

16. Mr. Friedman

(a)    As of the close of business on May 26, 2017, Mr. Friedman beneficially owned 346,865 Common Shares.

Percentage: Approximately 0.4%

(b)    i. Sole power to vote or direct vote: 346,865

ii. Shared power to vote or direct vote: 0

iii. Sole power to dispose or direct the disposition: 346,865

iv. Shared power to dispose or direct the disposition: 0

An aggregate of 5,632,242 Common Shares, constituting approximately 5.7% of the Common Shares outstanding, are reported in this Statement.

The Reporting Persons, as members of a group for the purposes of Section 13(d)(3) of the Securities Exchange Act of 1934, as
amended, may be deemed the beneficial owners of the Common Shares directly owned by the other Reporting Persons. Each Reporting Person disclaims beneficial ownership of such Common Shares except to the extent of his or its pecuniary interest
therein.

(c) Annex A attached hereto lists all transactions in the Common Shares during the past 60 days by the Reporting Persons. Except
as otherwise noted, the transactions in the Common Shares were effected in the open market.

(d) Not applicable.

(e) Not applicable.

Item 4 is hereby amended to add the following:

See Item 4 for a description of the Cooperation Agreement.

Item 7 is hereby amended and restated in its
entirety to read as follows:

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true,
complete and correct.

Dated: May 30, 2017

ANNEX A

TRANSACTIONS

The
following table sets forth all transactions with respect to the Common Shares effected in the last sixty days by the Reporting Persons on behalf of the Reporting Persons in respect of the Shares, inclusive of any transactions effected through 4:00
p.m., New York City time, on May 26, 2017.

EXHIBIT INDEX