INDEPENDENT VERDICT
M.D. Sass Income Opportunity, L.P. is a newly formed 2025 private fund inside a manager whose regulatory history stretches back decades. Its September 18, 2026 Form D/A reports $34,965,062 sold to nine investors under an indefinite Rule 506(b) offering and Section 3(c)(7), compared with $13.5 million sold to four investors in the original September 2025 filing. M.D. Sass Income Opportunity GP, LLC is the General Partner and M.D. Sass, LLC is the investment manager, with Bobby Liu signing as Chief Legal and Risk Officer of the manager. The fund also moved with the manager from 55 West 46th Street to 885 Third Avenue during 2026, giving the latest Form D a different address from the original filing without indicating a change in manager identity. The most interesting development, however, is broader: during the same period M.D. Sass launched a registered public ETF built around its long-running concentrated-value discipline, creating a useful contrast between a nine-investor private income vehicle and a fully registered exchange-traded strategy managed by the same firm.
THE PRIVATE FUND'S CAPITAL FORMATION ACCELERATED SHARPLY, BUT THE NINE-INVESTOR BASE REMAINS HIGHLY CONCENTRATED
The original September 18, 2025 Form D reported $13.5 million sold to four investors. Exactly one year later, the 2026 amendment increased cumulative securities sold to $34.965 million and investor count to nine. That is an increase of approximately $21.47 million, or about 159%, while only five additional investors were added. A simple average based on the current filing is roughly $3.9 million per investor, although actual allocations may differ substantially. This is useful because it distinguishes Income Opportunity from mass-distributed products: the regulatory footprint is still that of a concentrated private fund with a small LP base. Form D does not reveal whether the 2026 increase came from new investors, follow-on subscriptions by existing investors, or both, so the capital-formation trend should not be treated as a current NAV calculation.
THE FEE STRUCTURE IS UNUSUALLY VISIBLE FOR A PRIVATE FUND AND CREATES TWO DIFFERENT ECONOMIC PATHS
M.D. Sass's August 2026 Form ADV brochure describes two fee alternatives for the Income Opportunity Fund: a 0.65% management fee without an incentive fee, or a 0.25% management fee combined with a 5% incentive fee on appreciation. That is a much more informative disclosure than Form D provides and gives investors a direct way to analyze break-even economics between the two arrangements. It also creates a conflict framework that M.D. Sass itself acknowledges in its adviser materials: performance-based compensation can create incentives to take greater risk or favor accounts with higher economic value, while the firm says investment opportunities among similar strategies are allocated pro rata under its allocation policy. The exact share class or fee election used by each of the nine Income Opportunity investors is not public, so the headline fund size cannot be translated directly into manager revenue.
M.D. SASS'S PUBLIC EQUITY BOOK SHOWS A DISTINCT CONCENTRATED-VALUE PLATFORM THAT SHOULD NOT BE CONFUSED WITH INCOME OPPORTUNITY
M.D. Sass, LLC's public 13F reporting shows a sizeable U.S.-listed equity portfolio separate from the Income Opportunity fund. Q1 2026 reporting contained 36 positions valued at approximately $1.319 billion, led by Henry Schein, Williams Companies, Ametek, Clean Harbors and the RBB Fund Trust vehicle associated with the manager's concentrated-value strategy. The manager's Q2 2026 13F was filed August 7, 2026, confirming that this public-equity reporting remained active. The portfolio is relatively concentrated compared with many large institutional managers and aligns with M.D. Sass's historical fundamental-value identity. But 13F securities cannot simply be assigned to Income Opportunity: the adviser manages multiple mandates, separate accounts and registered vehicles, and 13F does not identify which client owns each reported position.
THE 2026 SASS ETF LAUNCH IS A MAJOR PLATFORM DEVELOPMENT BECAUSE IT TAKES A PRIVATE/INSTITUTIONAL INVESTMENT STYLE INTO A REGISTERED RETAIL WRAPPER
On February 4, 2026, The RBB Fund Trust filed an effective prospectus for the M.D. Sass Concentrated Equities ETF, later described as the M.D. Sass Concentrated Value ETF, ticker SASS. M.D. Sass, LLC serves as investment adviser and Tidal Investments LLC as sub-adviser. The ETF charges a 0.75% unitary management fee and seeks long-term capital appreciation through a non-diversified portfolio. The prospectus identifies Ari Sass, Martin D. Sass and Craig Barney as portfolio managers and discloses U.S. Bank Global Fund Services as administrator/transfer agent, U.S. Bank N.A. as custodian, PwC as independent auditor, Quasar Distributors as underwriter and Faegre Drinker as counsel. Most importantly, the filing reproduces a historical M.D. Sass Concentrated Value composite showing the investment process predates the ETF wrapper by many years. The ETF therefore represents distribution-format expansion, not creation of the investment philosophy in 2026.
THE MANAGER'S REGULATORY HISTORY REQUIRES ENTITY-LEVEL PRECISION BECAUSE THERE ARE TWO SIMILAR M.D. SASS NAMES
M.D. Sass, LLC, CRD 110590 / SEC 801-8663, remains the active investment adviser relevant to Income Opportunity. A separate entity, M.D. Sass Associates Inc., CRD 110596 / SEC 801-8670, terminated its SEC registration on March 31, 2023 and is no longer registered or filing as an adviser. Search results can easily mix the two. The active M.D. Sass LLC continues to employ registered advisory personnel, file Form 13F reports and serve as adviser to the 2026 SASS ETF. This distinction matters because describing the active fund manager using the terminated entity's status would produce a false regulatory conclusion.
FINAL ASSESSMENT
M.D. Sass Income Opportunity has at least eight case-specific facts that create a strong research story: it was formed in 2025; cumulative Form D sales rose from $13.5 million to $34.97 million in one year; investor count increased from four to nine; M.D. Sass LLC is the directly disclosed manager; the adviser offers two distinct Income Opportunity fee structures; the manager continues to run a $1 billion-plus public-equity book; the firm launched a registered SASS ETF in 2026 using its concentrated-value discipline; and the active M.D. Sass LLC must be distinguished from the separately terminated M.D. Sass Associates Inc. The key investor question is therefore strategy mapping: what securities and income sources specifically belong to Income Opportunity, how that mandate differs from concentrated value and other M.D. Sass accounts, and which fee arrangement each LP actually receives.
SEC SNAPSHOT
Issuer: M.D. Sass Income Opportunity, L.P. CIK: 0002084557 SEC Form: Form D/A Accession No.: 0000905148-26-004217 Filing Date: September 18, 2026 Formation Year: 2025 Jurisdiction: Delaware Principal Address: 885 Third Avenue, 26th Floor, New York, NY 10022 Telephone: 212-730-2000 Industry: Pooled Investment Fund Fund Classification: Other Investment Fund Investment Company Registered: No Investment Company Act Exclusion: Section 3(c)(7) Offering Exemption: Rule 506(b) Offering Amount: Indefinite Amount Sold: $34,965,062 Investors: 9 Minimum Investment: $0 reported First Sale: September 10, 2025 Offering Duration Over One Year: YES Sales Commissions: $0 Finder's Fees: $0 General Partner: M.D. Sass Income Opportunity GP, LLC Investment Manager: M.D. Sass, LLC Signer: Bobby Liu Signer Title: Chief Legal and Risk Officer of the Investment Manager
CAPITAL FORMATION HISTORY
September 18, 2025: Amount Sold: $13,500,000 Investors: 4
September 18, 2026: Amount Sold: $34,965,062 Investors: 9
Increase in Cumulative Securities Sold: $21,465,062
Percentage Increase: Approximately 159%
Investor Count Increase: 5
Simple Average 2026 Form D Amount Per Investor: Approximately $3.88 million
Actual Investor Allocations Publicly Disclosed: NO
Current Fund NAV Equal to $34.97M: NOT ESTABLISHED
FEE / ECONOMIC PENETRATION
Income Opportunity Fee Option 1: Management Fee: 0.65% Incentive Fee: None
Income Opportunity Fee Option 2: Management Fee: 0.25% Incentive Fee: 5% of appreciation
Exact Investor-by-Investor Election: Not public
Performance-Based Fee Conflict Disclosed by Adviser: YES
Adviser Allocation Policy: Pro rata across similarly managed accounts, according to adviser brochure
Complete Fund Expense Ratio: Not publicly confirmed
MANAGER / REGULATORY PENETRATION
Active Adviser: M.D. Sass, LLC
CRD: 110590
SEC File No.: 801-8663
SEC Registered Investment Adviser: YES
2026 ADV-Derived RAUM: Approximately $2.1 billion as of March 31, 2026
Separate February 2026 Registered-Fund Prospectus Statement: More than $3.1 billion AUM as of December 31, 2025
Those Figures Use Different Reporting Dates / Context: YES
They Should Be Treated as Automatically Identical: NO
Current Office: 885 Third Avenue, 26th Floor, New York
Prior 2025 Income Opportunity Address: 55 West 46th Street, 28th Floor
Manager Identity Changed: NO
SIMILAR-NAME REGULATORY CHECK
Separate Entity: M.D. Sass Associates Inc.
CRD: 110596
SEC File No.: 801-8670
SEC Registration Status: Terminated March 31, 2023
Same Legal Entity as M.D. Sass LLC: NO
Relevant Manager for Income Opportunity: M.D. Sass LLC
Potential Search-Result Confusion: HIGH
13F PENETRATION
13F Reporting Manager: M.D. Sass, LLC
CIK: 0000922940
13F File No.: 028-04057
Q1 2026 Holdings: 36
Q1 2026 Reported Value: Approximately $1.319 billion
Selected Q1 2026 Positions:
Henry Schein: Approximately $93.84 million
Williams Companies: Approximately $85.44 million
Ametek: Approximately $77.55 million
Clean Harbors: Approximately $72.41 million
RBB Fund Trust / M.D. Sass Concentrated Strategy: Approximately $66.93 million
Q2 2026 Form 13F Filed: August 7, 2026
13F Securities Proven to Be Income Opportunity Holdings: NO
13F Equal to Adviser RAUM: NO
13F Equal to Income Opportunity NAV: NO
REGISTERED ETF PENETRATION
Registered Vehicle: M.D. Sass Concentrated Value ETF
Ticker: SASS
Registrant: The RBB Fund Trust
Effective Launch Documentation: February 4, 2026
Investment Objective: Long-term capital appreciation
Investment Adviser: M.D. Sass, LLC
Investment Sub-Adviser: Tidal Investments LLC
Management Fee: 0.75%
Structure: Non-diversified registered open-end ETF
Portfolio Managers: Ari Sass, CFA Martin D. Sass Craig Barney, CFA
Administrator / Transfer Agent: U.S. Bank Global Fund Services
Custodian: U.S. Bank, N.A.
Independent Auditor: PricewaterhouseCoopers LLP
Underwriter: Quasar Distributors, LLC
Counsel: Faegre Drinker Biddle & Reath LLP
ETF Registered Under 1940 Act: YES
Income Opportunity Registered Under 1940 Act: NO
ETF Investors Own Income Opportunity: NO
Income Opportunity Investors Own ETF: NO
HISTORICAL CONCENTRATED-VALUE PENETRATION
M.D. Sass Concentrated Value Composite Predates ETF: YES
Historical Composite Published in ETF Registration Materials: YES
Selected Pro Forma Net Calendar-Year Returns Disclosed:
2019: Approximately 41.29%
2020: Approximately 7.60%
2021: Approximately 30.79%
2022: Approximately -5.44%
2023: Approximately 21.56%
2024: Approximately 9.37%
Historical Composite Equal to New ETF Return History: NO
Historical Composite Equal to Income Opportunity Return: NO
Past Composite Performance Guarantees Future Results: NO
PLATFORM HISTORY
Founder / Chairman: Martin D. Sass
President / Portfolio Manager: Ari Sass
Longstanding Institutional Investment Manager: YES
Public Equity / Value Management: YES
Income-Oriented Private Fund: YES
Registered ETF Business Added in 2026: YES
Historical Alternative Funds: M.D. Sass Multi-Strategy II M.D. Sass Multi-Strategy Partners M.D. Sass Maximus International New Heights Fund
Some Historical Funds Reported as Liquidated by Industry Databases: YES
Those Historical Liquidations Imply Income Opportunity Closure: NO
WEBSITE / ENTITY PENETRATION
M.D. Sass Income Opportunity SEC Issuer Confirmed: YES
M.D. Sass LLC Manager Relationship Confirmed: YES
Income Opportunity GP Confirmed: YES
M.D. Sass LLC CRD Confirmed: YES
SASS ETF SEC Registration Confirmed: YES
Tidal Sub-Advisory Role Confirmed: YES
PwC ETF Audit Role Confirmed: YES
U.S. Bank ETF Custodian / Administration Roles Confirmed: YES
Income Opportunity Complete Portfolio Publicly Disclosed: NO
Income Opportunity Auditor Confirmed: NO
Income Opportunity Administrator Confirmed: NO
Income Opportunity Custodian Confirmed: NO
Income Opportunity Prime Broker Confirmed: NO
Income Opportunity Current Yield Publicly Confirmed: NO
Income Opportunity Duration / Credit Allocation Publicly Confirmed: NO
CORE INVESTOR QUESTIONS
What securities actually make up M.D. Sass Income Opportunity Is the strategy primarily corporate credit, structured credit, preferred securities, convertibles, dividend equities or a multi-asset income mix What is the current fund NAV How much of the $34.97 million cumulative Form D sales remains invested Which of the nine investors selected the 0.65% management-fee structure Which selected the 0.25% plus 5% incentive structure What hurdle or high-water-mark terms apply to incentive compensation What is the current portfolio yield What is current duration What percentage of assets are investment grade What percentage are below investment grade Does the fund own equities also held in M.D. Sass's 13F accounts How are overlapping opportunities allocated between Income Opportunity and other M.D. Sass clients How does Income Opportunity differ from the public SASS ETF Are the same portfolio managers responsible for both What liquidity and redemption terms apply Can the GP impose gates or suspensions What leverage is permitted Who serves as current auditor Who serves as fund administrator Who serves as custodian or prime broker Why did adviser AUM references differ between the December 2025 ETF prospectus context and March 2026 ADV-derived data How much of any difference reflects client redemptions, market movements, reporting definitions or timing
PRIMARY EVIDENCE REVIEWED
SEC Form D/A for M.D. Sass Income Opportunity, L.P. filed September 18, 2026. Original SEC Form D for M.D. Sass Income Opportunity, L.P. filed September 18, 2025. SEC / IAPD record for M.D. Sass, LLC, CRD 110590 / SEC 801-8663. SEC / IAPD record for the separate M.D. Sass Associates Inc., CRD 110596 / SEC 801-8670, used to prevent entity conflation. M.D. Sass Form ADV Part 2A fee disclosures for Income Opportunity. M.D. Sass LLC Form 13F filing for Q2 2026 and prior quarterly 13F history. The RBB Fund Trust February 4, 2026 Form N-1A prospectus for the M.D. Sass Concentrated Value / Concentrated Equities ETF. ETF advisory and sub-advisory agreements between The RBB Fund Trust, M.D. Sass LLC and Tidal Investments LLC. ETF service-provider disclosures identifying U.S. Bank, PwC, Quasar and Faegre Drinker. Historical concentrated-value composite data contained in registered-fund materials.
IMPORTANT FORM D NOTICE
M.D. Sass Income Opportunity, L.P.'s September 18, 2026 Form D/A reports $34,965,062 of cumulative securities sold to nine investors. That figure is not automatically the fund's current NAV, M.D. Sass LLC's regulatory AUM or the value of the manager's Form 13F holdings. The M.D. Sass Concentrated Value ETF is a separate registered investment company and should not be treated as the same portfolio or legal vehicle as Income Opportunity. Likewise, M.D. Sass LLC and the separately terminated M.D. Sass Associates Inc. are different legal adviser entities. SEC registration, Form D filings, registered-fund prospectuses and historical performance composites are regulatory or disclosure evidence and do not constitute SEC approval or guarantee future performance.