Form ABS-15G DoubleLine Mortgage Oppo

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM ABS-15G

ASSET-BACKED SECURITIZER

REPORT PURSUANT TO SECTION 15G OF

THE SECURITIES EXCHANGE ACT OF 1934

Check the appropriate box to indicate the filing obligation to which this form is intended to satisfy:

Date of Report (Date of Filing): August 14, 2026

Date of Report (Date of earliest event reported)

DoubleLine Mortgage Opportunities Master Fund LP¹

(Exact name of securitizer as specified in its charter)

Mark Cho (213) 633-8200

Name and telephone number, including area code, of the person

to contact in connection with this filing

Indicate by check mark whether the securitizer has no activity to report for the initial period pursuant to Rule 15Ga-1(c)(1) ☐

Indicate by check mark whether the securitizer has no activity to report for the quarterly period pursuant to Rule 15Ga-1(c)(2)(i) ☐

Indicate by check mark whether the securitizer has no activity to report for the annual period pursuant to Rule 15Ga-1(c)(2)(ii) ☐

REPRESENTATION AND WARRANTY INFORMATION

Item 1.03 Notice of Termination of Duty to File Reports under Rule 15Ga-1

Pursuant to Rule 15Ga-1, DoubleLine Mortgage Opportunities Master Fund LP, as securitizer, is filing this Form ABS-15G to give notice of termination of its duty to file reports under Rule 15Ga-1 for the following affiliated entities:

Grand Avenue CRE 2019-FL1 Ltd.

Grand Avenue CRE 2020-FL2 Ltd.

The last payments made on the asset-backed securities issued by the following were paid as follows:

Grand Avenue CRE 2019-FL1 Ltd.: August 15, 2025

Grand Avenue CRE 2020-FL2 Ltd.: February 16, 2022

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the reporting entity has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: August 14, 2026