Firms, funds, partners, companies and rounds from sworn filings, firm sites and announcements, kept as a graph with a date and a source on every edge. Facts, inferences and estimates are labelled as such. A fund target is never a close, GAV is never dry powder, and a round size is never an investor’s check.

Firms / Mainline Investment Advisers, LLC

Mainline Investment Advisers, LLC

Private equity with venture activity · probableWynnewood, PAmainlineco.comSEC registered investment adviser

MainLine Investment Partners focuses on alternative investments in operating businesses & special opportunity real estate assets.

registered adviser; venture funds are 3% of 9 private funds

Importance
4
low
Active deployment
0
low
Emerging
0
low
Completeness
63
high
Freshness
100
high
Research priority
1
low
Identity and regulatory footprint
Headquarters
Wynnewood, PAadviserinfo.sec.gov
Office address
308 E. LANCASTER AVENUE, SUITE 300, Wynnewood, PA, 19096-2145adviserinfo.sec.gov
Business phone
610-896-3000adviserinfo.sec.gov
SEC adviser type
registered investment adviseradviserinfo.sec.gov
SEC exemption claimed
unknown
Latest Form ADV
Apr 28, 2026
Private funds reported
9 (1 venture capital funds)adviserinfo.sec.gov
Private fund gross assets
$108Madviserinfo.sec.govreported GAV of the funds, the adviser's own number; not fund size, not dry powder
Regulatory AUM
$110Mthe adviser's RAUM, a regulatory measure, never a fund size
Employees
4
Owners on Schedule A
Mainline Investment Partners, LLC (Sole Managing Member - 100% Owner), E
business email
info@mainlineco.commainlineco.compublished by the subject
business phone
610-896-3000adviserinfo.sec.govpublished by the subject
Stated thesis versus observed behaviour
no observed deals yet
Stated (the firm’s website)
Sectors
media
Stages
not stated or not yet read
Geography
not stated
Check size
not stated; DFX does not estimate checks from round sizes
Observed (from deals on record)
Stage at participation: no observed deals yet
Stage at first entry: no observed deals yet
Sectors: no observed deals yet
lead rate n/afollow-on rate n/anew logos, 12 months 0
Funds and vehicles
1 reported
VehicleTypeVintageLifecycleReported GAVOwnersForm D soldLatest Form D
Mainline Tu-K Industries, LLCFund2022 form d first saleActive deployment$5.7M
Jul 19, 2024
10$6.9M
of $6.9M
Nov 29, 2022
GAV is the gross asset value the adviser reported on Form ADV for the vehicle, never the fund’s committed size and never dry powder. Form D sold is the amount sold as of the latest filing, never a final close.
Investment team
6 current, 3 departed
3 departed (kept with end dates)
  • John Tucker Adams · Cfo, Treasurer, Vice President · Dec 1, 2014 to Mar 30, 2022 Inference
  • Richard Alan Mitchell · Chief Compliance Officer, General Counsel, Vice President And Secretary · Aug 1, 2011 to May 3, 2021 Inference
  • Matthew Warren Brown · Vice President · Aug 1, 2011 to Mar 30, 2021 Inference
Investments on record
0 edges, 0 companies, 0 partner-attributed
No investment on record yet. Edges arrive from the firm’s portfolio page, financing announcements, and Form D board seats.
Co-investors
0 relationships from shared deals, counted for the whole firm
No co-investor relationship yet: these are derived only from rounds and portfolio listings the graph has seen both investors on.
Limited partners
0 disclosed
No LP commitment on record. An LP edge needs a public disclosure with a quote: a pension report (see Limited partners for the plans read), a fund announcement naming the LP, or a Form ADV owner. The fund page carries the LP’s reported performance.
Timeline
9 dated events
  1. Mar 30, 2023
    Mainline Tu-K Industries, LLC first reported on Form ADV by Mainline Investment Advisers, LLC (Venture Capital Fund), GAV $7,198,235
  2. Mar 30, 2022
    John Tucker Adams (Cfo, Treasurer, Vice President) no longer on Schedule A of Mainline Investment Advisers, LLC
  3. Mar 1, 2022
    William J Romanelli joined Schedule A of Mainline Investment Advisers, LLC as Cfo, Treasurer And Vice President
  4. May 3, 2021
    Richard Alan Mitchell (Chief Compliance Officer, General Counsel, Vice President And Secretary) no longer on Schedule A of Mainline Investment Advisers, LLC
  5. Apr 1, 2021
    Donna Marie Rittershausen joined Schedule A of Mainline Investment Advisers, LLC as Secretary, Chief Compliance Officer
  6. Mar 30, 2021
    Matthew Warren Brown (Vice President) no longer on Schedule A of Mainline Investment Advisers, LLC
  7. Aug 1, 2015
    Alexander C Chadwick joined Schedule A of Mainline Investment Advisers, LLC as Vice President
  8. Dec 1, 2014
    John Tucker Adams joined Schedule A of Mainline Investment Advisers, LLC as Cfo, Treasurer, Vice President
  9. Jan 24, 2012
    Mainline Investment Advisers, LLC first filed Form ADV (IA)
Classification history
  1. Sep 12, 2026
    Private equity with venture activity (probable, 75%, cls-1)
    registered adviser; venture funds are 3% of 9 private funds
  2. Sep 12, 2026
    Private equity with venture activity (probable, 75%, cls-1)
    registered adviser; venture funds are 3% of 7 private funds
Evidence
75 observations from 3 sources
Every observation behind this profile, with its source, date and class
FactValueEffectiveClassSource
Why admittedvc_funds_reportedApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
SEC adviser typeregistered_investment_adviserApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
SEC adviser typeregistered_investment_adviserJul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
First Form ADV filing2012-01-24Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Adv history loadedadv-hist-1Sep 12, 2026FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Latest Form ADV filing2026-04-28Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Latest Form ADV filing2024-07-19Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
SEC statusApprovedApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
SEC status effective2011-10-05Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Venture share of reported funds0Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Business phone610-896-3000Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Business phone610-896-3000Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Contact page urlhttps://mainlineco.com/contact-us/
contact page linked from the home page
Sep 16, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
DescriptionMainLine Investment Partners focuses on alternative investments in operating businesses & special opportunity real estate assets.
meta description
Sep 16, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
DescriptionMainLine Investment Partners focuses on alternative investments in operating businesses & special opportunity real estate assets.
meta description
Sep 15, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Employees4Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Employees6Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
HeadquartersWynnewood, PAApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
HeadquartersWynnewood, PAJul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Office address308 E. LANCASTER AVENUE, SUITE 300, Wynnewood, PA, 19096-2145Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Office address308 E. LANCASTER AVENUE, SUITE 300, Wynnewood, PA, 19096-2145Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Legal formLimited Liability CompanyApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
PE funds reported7Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Private funds reported9Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Private funds reported7Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Private fund gross assets (reported)$108MApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Private fund gross assets (reported)$240MJul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Regulatory AUM (adviser, not fund size)$110MApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Regulatory AUM (adviser, not fund size)$245MJul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Stated sectorsmedia
sector words on the home page
Sep 16, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Stated sectorsmedia
sector words on the home page
Sep 15, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Team pagehttps://mainlineco.com/team/
1 name/title pairs read
Sep 16, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Team pagehttps://mainlineco.com/team/
1 name/title pairs read
Sep 15, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Venture funds reported1Apr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
Venture funds reported1Jul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
WebsiteHTTPS://WWW.MAINLINEINVESTMENTADVISERS.COMApr 28, 2026FactSEC Form ADV monthly roster (registered + exempt reporting advisers)
WebsiteHTTP://WWW.MAINLINECO.COMJul 19, 2024FactSEC Form ADV filing data 2011 to 2024 (every filing, Schedule D 7.B.(1) private funds, Schedules A/B)
Site titleMainline Investment Partners - Wynnewood, Pa
title tag
Sep 16, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)
Site titleMainline Investment Partners - Wynnewood, Pa
title tag
Sep 15, 2026FactVenture organization websites (about, team, portfolio, thesis, news pages)