Firm profile

Diameter Principal Finance LLC

NEW YORK, NYCRD 328057Registration Status: ApprovedEffective since October 24, 2023SEC # 801-128935Latest ADV April 29, 2026

Diameter Principal Finance LLC is an SEC registered investment adviser organized as a limited liability company with a primary office location in New York, NY. Its latest Form ADV filing, dated April 29, 2026, reports $3.4B in regulatory assets under management, 119 employees, 3 offices, and 1 account.

Assets Under Management
$3.4B
Employees
119
Offices
3 offices
Total Clients
<5

Associated firm names

1 name listed
  • DIAMETER PRINCIPAL FINANCE LLC

Leadership

4 roles identified
CEOJonathan N. Lewinsohn
CEOScott K. Goodwin
CCOMichael J. Cohn

Advisory services offered

1 types reported
Portfolio management for investment companies

Fee models offered

2 types reported
Asset based fees
Performance-based fees

Offices & Contact

Primary office

NEW YORK, New York, United States

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Primary office regionOther reported regions

Shading shows states and countries with reported offices. Cities are listed below; shading does not indicate service coverage.

New York

NEW YORKPrimary office

Florida

WEST PALM BEACH

United Kingdom

LONDON

3 office records listed · 3 total offices reported. Counts can use different reporting dates. SEC filers may list only their largest 25 additional offices.

Contact and digital presence

ADV profile links

Regulatory Assets Under Management Breakdown

Total regulatory assets under management$3.4Bas of April 29, 2026
Discretionary100.0%
$3.4B
100% of total RAUM100.0%
Non-discretionary0.0%
$0
0% of total RAUM0.0%
All regulatory assets under management are discretionary.

Client Coverage Demographics

Top client segmentBDCs represent 100.0% of total clients.
Top client categories% of clientsClients
1
BDCs
100.0%
1

Assets under management Growth by Quarter

Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.

Total AUM$3.4B
Total Accounts1
10Y AUM Change+$3.4B

Private Funds

Private funds reported by Diameter Principal Finance LLC

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Employee Growth by Quarter

Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.

Total Employees119
Clients per Employee0:1
10Y Employee Change+64 (+116.4%)

Historical AUM and employee figures reflect available SEC Form ADV filings under this CRD. Filing gaps may reflect registration status changes, dormant periods, state registration periods, firm restructuring, or other reporting changes. Rialytix does not interpolate missing periods.


Ownership

Reported direct and indirect ownership ranges

Each range applies to a separate reported relationship and should not be added together.

Reported ownership ranges

Highlighted bands show the percentage range reported in Form ADV.

0%25%50%75%100%
DIAMETER PRINCIPAL FINANCE PARTNERSHIP LPDirect owner · Schedule AInterest in DIAMETER PRINCIPAL FINANCE LLC
75%+
BENJAMIN DAVID PASTERNACKDirect owner · Schedule AInterest in DIAMETER PRINCIPAL FINANCE LLC
< 5%
JOSEPH ALEXANDER CARVALHODirect owner · Schedule AInterest in DIAMETER PRINCIPAL FINANCE LLC
< 5%
DIAMETER PRINCIPAL FINANCE FEEDER LPIndirect owner · Schedule BInterest in DIAMETER PRINCIPAL FINANCE PARTNERSHIP LP
75%+
JONATHAN NMN LEWINSOHNIndirect owner · Schedule BInterest in DIAMETER MANAGEMENT INTERMEDIATE LP
75%+
SCOTT KREITLER GOODWINIndirect owner · Schedule BInterest in SG DIAMETER LLC
75%+
DIAMETER CAPITAL PARTNERS LPIndirect owner · Schedule BInterest in DIAMETER PRINCIPAL FINANCE HOLDINGS LLC
75%+
DIAMETER CAPITAL PARTNERS LPIndirect owner · Schedule BInterest in DIAMETER PRINCIPAL FINANCE FEEDER LP
50% to < 75%
JONATHAN NMN LEWINSOHNIndirect owner · Schedule BInterest in DIAMETER CAPITAL PARTNERS GP LLC
50% to < 75%
SCOTT KREITLER GOODWINIndirect owner · Schedule BInterest in DIAMETER CAPITAL PARTNERS GP LLC
50% to < 75%
DIAMETER MANAGEMENT INTERMEDIATE LPIndirect owner · Schedule BInterest in DIAMETER CAPITAL PARTNERS LP
25% to < 50%
SG DIAMETER LLCIndirect owner · Schedule BInterest in DIAMETER CAPITAL PARTNERS LP
25% to < 50%
JOSEPH ALEXANDER CARVALHOIndirect owner · Schedule BInterest in DIAMETER PRINCIPAL FINANCE FEEDER LP
25% to < 50%
BENJAMIN DAVID PASTERNACKIndirect owner · Schedule BInterest in DIAMETER PRINCIPAL FINANCE FEEDER LP
25% to < 50%

Bars represent the reported range at that individual ownership step, not an estimated percentage of the advisory firm. Indirect relationships may refer to intermediate entities rather than directly to Diameter Principal Finance LLC.

Reported ownership and control details

Form ADV · Filing date 2026-04-29 · Schedules A and B

21 entries
#Owner / person & roleInterest in entityReported interestControl personTitle / status acquiredSource
1SCOTT KREITLER GOODWINCO-CHIEF EXECUTIVE OFFICER & CO-PRESIDENTIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesCO-CHIEF EXECUTIVE OFFICER & CO-PRESIDENT02/2022Schedule APDF page 24
2JONATHAN NMN LEWINSOHNCO-CHIEF EXECUTIVE OFFICER & CO-PRESIDENTIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesCO-CHIEF EXECUTIVE OFFICER & CO-PRESIDENT02/2022Schedule APDF page 24
3DIAMETER PRINCIPAL FINANCE PARTNERSHIP LPSOLE MEMBERDomestic entityDIAMETER PRINCIPAL FINANCE LLC75% or moreCode EYesSOLE MEMBER06/2022Schedule APDF page 24
4BENJAMIN DAVID PASTERNACKCO-HEAD & PARTNERIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesCO-HEAD & PARTNER06/2023Schedule APDF page 24
5JOSEPH ALEXANDER CARVALHOCO-HEAD & PARTNERIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesCO-HEAD & PARTNER06/2023Schedule APDF page 24
6MICHAEL JOSHUA COHNGENERAL COUNSEL AND CHIEF COMPLIANCE OFFICERIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesGENERAL COUNSEL AND CHIEF COMPLIANCE OFFICER08/2024Schedule APDF page 24
7MATTHEW GERARD GILMARTINCHIEF FINANCIAL OFFICERIndividualDIAMETER PRINCIPAL FINANCE LLCLess than 5%Code NAYesCHIEF FINANCIAL OFFICER03/2026Schedule APDF page 24
8DIAMETER PRINCIPAL FINANCE FEEDER LPLIMITED PARTNERDomestic entityDIAMETER PRINCIPAL FINANCE PARTNERSHIP LP75% or moreCode EYesLIMITED PARTNER06/2022Schedule BPDF page 25
9DIAMETER PRINCIPAL FINANCE HOLDINGS LLCGENERAL PARTNERDomestic entityDIAMETER PRINCIPAL FINANCE PARTNERSHIP LPPercentage not specifiedCode FYesGENERAL PARTNER06/2022Schedule BPDF page 25
10DIAMETER CAPITAL PARTNERS LPLIMITED PARTNERDomestic entityDIAMETER PRINCIPAL FINANCE FEEDER LP50% to less than 75%Code DYesLIMITED PARTNER06/2022Schedule BPDF page 25
11DIAMETER PRINCIPAL FINANCE HOLDINGS LLCGENERAL PARTNERDomestic entityDIAMETER PRINCIPAL FINANCE FEEDER LPPercentage not specifiedCode FYesGENERAL PARTNER06/2022Schedule BPDF page 25
12DIAMETER CAPITAL PARTNERS GP LLCGENERAL PARTNERDomestic entityDIAMETER CAPITAL PARTNERS LPPercentage not specifiedCode FYesGENERAL PARTNER11/2016Schedule BPDF page 25
13DIAMETER MANAGEMENT INTERMEDIATE LPLIMITED PARTNERDomestic entityDIAMETER CAPITAL PARTNERS LP25% to less than 50%Code CYesLIMITED PARTNER07/2021Schedule BPDF page 25
14SG DIAMETER LLCLIMITED PARTNERDomestic entityDIAMETER CAPITAL PARTNERS LP25% to less than 50%Code CYesLIMITED PARTNER07/2021Schedule BPDF page 25
15JONATHAN NMN LEWINSOHNMEMBERIndividualDIAMETER CAPITAL PARTNERS GP LLC50% to less than 75%Code DYesMEMBER11/2016Schedule BPDF page 25
16SCOTT KREITLER GOODWINMEMBERIndividualDIAMETER CAPITAL PARTNERS GP LLC50% to less than 75%Code DYesMEMBER11/2016Schedule BPDF page 25
17JONATHAN NMN LEWINSOHNLIMITED PARTNERIndividualDIAMETER MANAGEMENT INTERMEDIATE LP75% or moreCode EYesLIMITED PARTNER07/2021Schedule BPDF page 25
18SCOTT KREITLER GOODWINMEMBERIndividualSG DIAMETER LLC75% or moreCode EYesMEMBER07/2021Schedule BPDF page 25
19DIAMETER CAPITAL PARTNERS LPSOLE MEMBERDomestic entityDIAMETER PRINCIPAL FINANCE HOLDINGS LLC75% or moreCode EYesSOLE MEMBER06/2022Schedule BPDF page 25
20JOSEPH ALEXANDER CARVALHOLIMITED PARTNERIndividualDIAMETER PRINCIPAL FINANCE FEEDER LP25% to less than 50%Code CYesLIMITED PARTNER06/2022Schedule BPDF page 25
21BENJAMIN DAVID PASTERNACKLIMITED PARTNERIndividualDIAMETER PRINCIPAL FINANCE FEEDER LP25% to less than 50%Code CYesLIMITED PARTNER06/2022Schedule BPDF page 25

Less than 5% may include zero. Code F identifies a role without specifying a percentage. Reported interests may overlap and may not include every owner. Total indirect ownership is not calculated.

Compliance & Disclosures

Filing dated 4/29/2026 1:12:47 PM

Responses were selected by the RIA in its filing. Questions are shortened for readability; “you” refers to the reporting firm, and some questions also cover advisory affiliates.

RIA or supervised-person involvementThe RIA reported that none of the events below involve the firm or its supervised persons.RIA responseNo
AFelonies2 No

In the past ten years, have you or any advisory affiliate:

  • A1Been convicted of or pleaded guilty or no contest to a felony?No
  • A2Been charged with a felony?No
BMisdemeanors2 No

In the past ten years, have you or any advisory affiliate:

  • B1Been convicted of or pleaded guilty or no contest to a misdemeanor involving investments, an investment-related business, fraud, false statements or omissions, wrongful taking of property, bribery, perjury, forgery, counterfeiting, or extortion?No
  • B2Been charged with a misdemeanor of the kind listed above?No
CSEC or CFTC actions5 No

Has the SEC or CFTC ever:

  • C1Found you or an advisory affiliate made a false statement or omission?No
  • C2Found you or an advisory affiliate violated SEC or CFTC regulations or statutes?No
  • C3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?No
  • C4Entered an order against you or an advisory affiliate in connection with investment-related activity?No
  • C5Imposed a civil money penalty on you or an advisory affiliate, or ordered you or an advisory affiliate to cease and desist from any activity?No
DOther regulatory actions5 No

Has any other federal regulatory agency, state regulatory agency, or foreign financial regulatory authority ever:

  • D1Found you or an advisory affiliate made a false statement or omission, or was dishonest, unfair, or unethical?No
  • D2Found you or an advisory affiliate violated investment-related regulations or statutes?No
  • D3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?No
  • D4In the past ten years, entered an order against you or an advisory affiliate in connection with investment-related activity?No
  • D5Denied, suspended, or revoked your or an advisory affiliate’s registration or license, or otherwise prevented association with an investment-related business or restricted activities?No
ESelf-regulatory organization actions4 No

Has a self-regulatory organization or commodities exchange ever:

  • E1Found you or an advisory affiliate made a false statement or omission?No
  • E2Found you or an advisory affiliate violated its rules, other than a violation designated as a minor rule violation under an SEC-approved plan?No
  • E3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?No
  • E4Disciplined you or an advisory affiliate by expulsion, suspension, barring association with other members, or otherwise restricting activities?No
FProfessional authorizations1 No
  • FHas an authorization to act as an attorney, accountant, or federal contractor granted to you or an advisory affiliate ever been revoked or suspended?No
GPending regulatory proceedings1 No
  • GAre you or any advisory affiliate now the subject of a regulatory proceeding that could result in a “Yes” answer to any part of C, D, or E?No
HCivil judicial actions and proceedings4 No

(1) Court actions

Has a domestic or foreign court:

  • H(1)(a)In the past ten years, enjoined you or an advisory affiliate in connection with investment-related activity?No
  • H(1)(b)Found that you or an advisory affiliate violated investment-related statutes or regulations?No
  • H(1)(c)Dismissed, pursuant to a settlement agreement, an investment-related civil action brought against you or an advisory affiliate by a state or foreign financial regulatory authority?No

(2) Pending civil proceedings

  • H(2)Are you or any advisory affiliate now the subject of a civil proceeding that could result in a “Yes” answer to any part of H(1)?No

* Metrics are based on the latest available data, including Form ADV filings, brochures, and relationship summaries pulled from the SEC IAPD, and may be subject to change. Learn what is included in the Rialytix data. Please refer to the firm's official disclosures for the most accurate information using their CRD number. This is not investment advice.