Wealth manager, independent · Lakeville, CT
Main Street Research LLC
SEC-registered investment adviser · CRD 114629 · SEC 801-57739
At a glance
Main Street Research LLC is an SEC-registered investment adviser based in Lakeville, Connecticut, with $2.7B in regulatory assets under management as of its Form ADV filed April 27, 2026. It reports 1,018 individual clients, 815 of them high-net-worth, holding an average of about $2.6 million each, and 24 employees. That ranks it 414th among the nation’s 5,657 independent wealth management RIAs and 10th of 100 in Connecticut. It reports Charles Schwab as the custodian for its clients’ separately managed accounts.
Main office 860-435-2350ms-research.comLinkedInAs filed on Form ADV
- Regulatory AUM
- $2.7B
- Rank among independent wealth managers
- #414 of 5,657
- Rank among all SEC RIAs
- #3,040 of 17,210
- Rank in Connecticut
- #10 of 100
- Individual clients
- 1,018
- High-net-worth clients
- 815
- Accounts
- 3,017
- Discretionary
- 100% of AUM
- Employees
- 24
- Advisory staff
- 16
- Offices
- 5
Owners and executives on its Form ADV
- James E. DemmertManaging Partner and Chief Investment Officer
- Benjamin B ArmelliniPartner - Chief Executive Officer
- Aaron M. SternManaging Partner and Portfolio Manager
- Natalie E. McMahonManaging Partner
- Natalie E. McMahonChief Compliance Officer
- Lily N. TaftManaging Partner
Custody and brokerage
Broker-dealer
No broker-dealer ties
Main Street Research LLC reports no employees registered with a broker-dealer and no affiliated broker-dealer.
Who it serves
| Client type | Clients | Regulatory AUM | Share |
|---|---|---|---|
| High-net-worth individuals | 815 | $2.6B | 95% |
| Individuals | 203 | $68M | 3% |
| Charitable organizations | 5 | $44M | 2% |
| Pension and profit sharing plans | 8 | $17M | <1% |
Disciplinary disclosures
Main Street Research LLC reports no disciplinary disclosures in Item 11 of Form ADV. Read the details on the SEC’s adviser search ↗
Services
- Financial planning
- Portfolio management for individuals and small businesses
- Portfolio management for businesses and institutions
- Educational seminars and workshops
- Other services
How it’s paid
- A percentage of assets under management
- Performance-based fees
Form ADV and brochures on the SEC’s adviser search ↗ms-research.com ↗
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Ten years of SEC filings, its owners and contacts, and how it stacks up against its peers. Atlas members see all of it.
- Assets, accounts, clients and staff, ten years of filings
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- Growth over one, three and five years
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- Rank against 1,507 peers of its type and size
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- Owners and executives, with titles and stakes
- 6 namedLocked
- Main office, fax and compliance officer
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- Filing changes this year, with alerts
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Free while Atlas launches: create a free account and confirm your email. Every figure comes from SEC filings.
Similar-size RIAs in Connecticut
All of Connecticut →| Firm | Regulatory AUM | Clients |
|---|---|---|
| Greenwich Wealth Management, LLCGreenwich | $3.5B | 589 |
| Principle WealthMadison | $3.2B | 1,173 |
| Johnson BrunettiWethersfield | $2.8B | 6,038 |
| RZH Advisors LLCStamford | $2.4B | 451 |
| Moneco AdvisorsFairfield | $2.3B | 2,781 |
| Clear Harbor Asset Management, LLCStamford | $2.1B | 784 |
Background
Questions
How much does Main Street Research LLC manage?
Main Street Research LLC reports $2.7B in regulatory assets under management across 3,017 accounts, 100% of it on a discretionary basis, on its Form ADV filed April 27, 2026.
How many clients does Main Street Research LLC have?
It reports 1,018 individual clients: 815 high-net-worth individuals and 203 other individuals. Individuals account for about 98% of its regulatory assets.
Where is Main Street Research LLC headquartered?
Its main office is in Lakeville, Connecticut. It reports 5 offices in total and 24 employees, 16 of whom perform investment advisory functions.
How does Main Street Research LLC charge clients?
On Form ADV it lists these forms of compensation: a percentage of assets under management; performance-based fees. Fees and minimums are set out in its Form ADV Part 2A brochure, available on the SEC’s adviser search.
What custodian does Main Street Research LLC use?
It reports Charles Schwab as the custodian for its clients’ separately managed accounts. On Schedule D of its Form ADV filed April 27, 2026, it reports these amounts held: Charles Schwab ($2.7B). Form ADV lists only custodians holding 10% or more of separately managed account assets.
Is Main Street Research LLC a hybrid RIA with a broker-dealer?
Main Street Research LLC reports no employees registered with a broker-dealer and no affiliated broker-dealer.
Is Main Street Research LLC a fiduciary?
As an SEC-registered investment adviser, Main Street Research LLC owes its advisory clients a fiduciary duty under the Investment Advisers Act of 1940, which includes duties of care and loyalty. It reports no employees who are registered representatives of a broker-dealer.
Where these numbers come from
Every figure is Main Street Research LLC’s own answer on its latest Form ADV, from the SEC’s registered-adviser list as of October 1, 2026: regulatory assets and accounts (Item 5.F), clients by type (5.D), employees (5.A and 5.B), compensation (5.E) and services (5.G). Custodians come from Schedule D 5.K(3) of its latest filing (2026-04-27), which lists those holding 10% or more of separately managed account assets and the amount at each. “Hybrid” means some employees are also registered representatives of a broker-dealer (Item 5.B(2)); affiliated broker-dealers are the related persons it lists in Item 7.A and Schedule D. Firm type comes from its own answers: broker-dealer firms are registered broker-dealers themselves (Item 6.A); private fund advisers manage mostly private funds (Item 7.B, 5.D); wealth managers manage at least half their assets for individuals (5.D). Its national rank compares it with every US-based independent wealth management RIA, the same field as The Largest RIAs. Figures are as of the firm’s last annual update, so they can lag recent deals and market moves. Regulatory AUM counts assets the firm continuously supervises and can differ from what a firm markets.
Not an endorsement or a recommendation. Before hiring any adviser, read its Form ADV Part 2A brochure and check its record on the SEC’s adviser search. How to check a financial advisor →