UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q/A

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF

THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2026

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from _____ to _____

Commission File No. 814-01754

SL Investment Fund II LLC

(Exact name of registrant as specified in charter)

1 212-761-4000

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days: Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☒

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

The number of the registrant’s common units, $0.001 par value outstanding at May 14, 2026 was 18,113,703.

EXPLANATORY NOTE

SL Investment Fund II LLC (the “Company”, “we”, “us” or “our”) is filing this Amendment No. 1 (the “Amendment”) to our Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, which was filed with the Securities and Exchange Commission (the “SEC”) on May 14, 2026 (the “Form 10-Q”). The Company inadvertently omitted certain information from the certifications of its chief executive officer and its chief financial officer that were included with the Form 10-Q. The Company is filing this Amendment solely to include the revised certifications of the Company’s chief executive officer and chief financial officer.

Except as described above, this Amendment does not modify or update disclosure in, or exhibits to, the Form 10-Q. Furthermore, this Amendment does not change any previously reported financial results, nor does it reflect events occurring after the filing date of the Form 10-Q. This Amendment should be read in conjunction with the Form 10-Q and with our filings with the SEC subsequent to the Form 10-Q.

PART II - OTHER INFORMATION

Item 6. Exhibits

The following exhibits are filed as part of this Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this Report to be signed on its behalf by the undersigned thereunto duly authorized.