Main Street Research LLC

• A percentage of assets under your management
• Performance-based fees

Item 5.E lists how the firm is compensated for its advice; Items 5.B, 6.A, and 7.A show whether its people or related companies can also earn commissions. Percentage of assets, fixed, hourly, subscription, and performance-based fees come from clients (a performance-based fee depends on investment results); commissions come with a sale or a trade, often from the company behind the product. How fees, commissions, and other arrangements differ

The brochure lists different fees for different services or strategies; see the brochure for them.

Minimum annual fee: None

As stated in the firm's Form ADV Part 2A brochure dated March 31, 2026. Fees can differ by service and may be negotiable; the brochure is the complete statement. Read the brochure on the SEC's IAPD site

$2,681,886,634 as of October 2026, filing dated April 27, 2026.

A measure of scale, not skill or returns. Discretionary means the firm decides trades; non-discretionary means clients approve each one. What assets under management means

A firm with no individual clients is an institutional manager even if it manages billions; the mix tells you whom the practice is built around.

• Financial planning services
• Portfolio management for individuals and/or small businesses
• Portfolio management for businesses (other than small businesses) or institutional clients
• Educational seminars/workshops
• Other

Registration

SEC-registered investment adviser. Status as filed: Approved.

Registered since

2000 (25 years)

Employees

Total: 24. Performing investment advisory functions: 16.

Wrap fee program participation

No.

Custodians (Schedule D, Section 5.K(3))

Charles Schwab & Co., Inc.

Custodians holding 10% or more of the firm's separately managed account assets, as filed on Form ADV (Schedule D, Section 5.K(3)). A custodian holds client assets; it does not endorse or supervise the firm. AdvisorCensus has no relationship with any custodian.

Other offices (Schedule D, Section 1.F)

4 other offices, as of the May 2026 filing

Greenwich, CTLakeville, CTNew York, NYSausalito, CA

States registered or notice-filed

42 states or jurisdictions

ALARAZCACOCTDCDEFLGAHIIAILINKYLAMAMDMEMIMNMOMTNCNDNHNJNMNVNYOHORPARISCTNTXUTVAVTWAWV

SEC-registered investment advisers are examined by the SEC. SEC, state, and exempt registration

None Reports no disclosure items on Form ADV Item 11. View on IAPD.

Item 11 asks about criminal, regulatory, and civil events involving the firm and its advisory personnel. The detail of each yes answer is on the IAPD record. Reading a firm's disclosures

Regulatory assets under management: $1,389,974,082 in the October 2021 data and $2,681,886,634 in the October 2026 data, up 93%.

Total employees: 13 in October 2021 and 24 in October 2026.

As filed in each year's data for the same month. Assets under management move with markets as well as with clients coming and going; they measure scale, not skill or returns. Most firms update these figures once a year.

1. April 2026
   • Regulatory assets under management went from $2,384,657,948 to $2,681,886,634 (+12%).
   • Updated its list of owners and control persons (Schedule A).

Compared month to month from the SEC's monthly adviser data and the state compilation feed. Owners and control persons are summarized, never named.