O'Brien Investment Management provides portfolio management for individuals and small businesses.
O'Brien Investment Management reports 167 clients. They include 96 high-net-worth individuals, 69 individual clients, and 2 pension and profit-sharing plans. Of its assets, 100.0% ($254M across 334 accounts) are managed with discretion.
| Client type | Clients | Assets |
|---|---|---|
| Individuals (other than HNW) | 41% | 4% |
| High-net-worth individuals | 57% | 94% |
| Pension and profit-sharing plans | 1% | 2% |
Client breakdown and activity details
| Client type | Clients | Regulatory AUM | AUM share | Avg. per client |
|---|---|---|---|---|
| Individuals (other than HNW) | 69 | $11M | 4.3% | $160K |
| High-net-worth individuals | 96 | $238M | 93.7% | $2.48M |
| Pension and profit-sharing plans | Fewer than 5 | $4.91M | 1.9% | $2.46M |
| Total | 167 | $254M | 100% | — |
- Clients
- 69
- Regulatory AUM
- $11M
- AUM share
- 4.3%
- Avg. per client
- $160K
- Clients
- 96
- Regulatory AUM
- $238M
- AUM share
- 93.7%
- Avg. per client
- $2.48M
- Clients
- Fewer than 5
- Regulatory AUM
- $4.91M
- AUM share
- 1.9%
- Avg. per client
- $2.46M
Total
- Clients
- 167
- Regulatory AUM
- $254M
- AUM share
- 100%
- Avg. per client
- —
- Clients outside the U.S.
- 0%
- Clients advised without assets under management last fiscal year
- 0
- Private funds advised
- 0
- Financial planning clients last fiscal year
- 0
O'Brien Investment Management charges 0.50%–1.00% a year for its Investment management services. Each asset band is charged at its own rate. The fee is billed in arrears and is negotiable.
| Asset band | Annual rate |
|---|---|
| $0–$1M | 1.00% |
| $1M–$3M | 0.90% |
| $3M–$5M | 0.75% |
| $5M–$10M | 0.60% |
| $10M and above | 0.50% |
Fee details and sources
Michael O'Brien owns 75% or more of O'Brien Investment Management. The leadership team of O'Brien Investment Management includes President Michael O'Brien. It has 3 employees, 2 of them in advisory roles.
Leadership
- Michael O'BrienPresident, Chief Compliance Officer
- John O'BrienPartner
Investment adviser representatives
2 representatives listed in the SEC register as of 9 October 2026.
- John Shiels O'Brien
- Michael Dennis O'Brien
Staff
- 3 employees
- 2 in advisory functions
- 2 state-registered reps
- Owns 75% or more of O'Brien Investment Management, LLC
Michael O'Brien
Control person · since May 2016
- Owns 25% to 50% of O'Brien Investment Management, LLC
John O'Brien
Control person · since September 2020
O'Brien Investment Management’s regulatory assets grew 1.7× from $154M (June 2021) to $254M (August 2026); clients rose from 97 to 167 and employees fell from 4 to 3.
Figures from each annual filing
| Filed | Regulatory AUM | Clients | Employees | Offices |
|---|---|---|---|---|
| August 2026 | $254M | 167 | 3 | 1 |
| March 2025 | $231M | 157 | 3 | 1 |
| March 2024 | $193M | 130 | 3 | 1 |
| March 2023 | $154M | 109 | 3 | 1 |
| March 2022 | $172M | 104 | 4 | 1 |
| June 2021 | $154M | 97 | 4 | 1 |
Besides its headquarters, O'Brien Investment Management has 0 offices, with 1 listed address in California.
California · 1 listed address
- 24594 Hawthorne BLVD., TorranceHQ
Contact and registration details
- Legal name
- O'Brien Investment Management, LLC
- Headquarters
- 24594 Hawthorne BLVD., Torrance, CA 90505
- Website
- obrienim.com
- Phone
- 310-363-2360
- SEC file
- 801-118289
- Founded
- 2016
- Structure
- California LLC
- Fiscal year end
- December
O'Brien Investment Management uses Fidelity ($163M, 97%) and Charles Schwab ($4.44M, 3%) as custodians for its separately managed accounts. O'Brien Investment Management has custody of $132M in client assets for 62 clients.
- FidelityNational Financial Services LLC · Boston, MA · $163M97%
- Charles SchwabCharles Schwab & Co., Inc. · San Francisco, CA · $4.44M3%
At year end, O'Brien Investment Management’s separately managed accounts were mostly in stocks (56%) and bonds (20%).
What the accounts hold
- Stocks56%
- Funds6%
- Bonds20%
- U.S. government and agency bonds17%
- State and local bonds3%
- Cash17%
Filed values cover 99%. The neutral 1% gap has no reported category.
How many clients does O'Brien Investment Management have?
O'Brien Investment Management has 167 clients and manages $254 million for them, as of August 2026. They include 96 high-net-worth individuals, 69 individual clients, and 2 pension and profit-sharing plans.
Source: Form ADV Part 1A, Items 5.D and 5.F, filed 27 August 2026
What services does O'Brien Investment Management offer?
O'Brien Investment Management provides portfolio management for individuals and small businesses.
Source: Form ADV Part 1A, Item 5.G, from the SEC's 2 October 2026 data file
How much does O'Brien Investment Management charge?
O'Brien Investment Management charges 0.50%–1.00% a year for its Investment management services. Each asset band is charged at its own rate. The fee is billed in arrears and is negotiable.
Which custodians does O'Brien Investment Management use?
O'Brien Investment Management’s separately managed account assets are held at National Financial Services LLC (Boston, MA), with $163M and Charles Schwab & Co., Inc. (San Francisco, CA), with $4.44M. Only custodians holding at least a tenth of those assets are named.
Source: Form ADV Part 1A, Schedule D, Section 5.K.(3), filed 27 August 2026
How many financial advisors does O'Brien Investment Management have?
O'Brien Investment Management has 2 investment adviser representatives registered with state securities authorities, out of 3 employees, and 2 perform investment advisory functions. None are registered representatives of a broker-dealer or licensed insurance agents.
Source: Form ADV Part 1A, Items 5.A and 5.B, from the SEC's 2 October 2026 data file
What does O'Brien Investment Management invest in?
At the end of its last fiscal year, O'Brien Investment Management’s separately managed accounts held 56% exchange-traded equities, 17% U.S. government and agency bonds, 17% cash and equivalents, 6% registered funds (mutual funds, ETFs, BDCs) and 3% state and local bonds.
Source: Form ADV Part 1A, Items 5.K.(1) and 7.B, from the SEC's 2 October 2026 data file
Who owns O'Brien Investment Management?
O'Brien Investment Management’s direct owners are Michael O'Brien (75% or more) and John O'Brien (25% to 50%).
Source: Form ADV Part 1A, Schedules A and B, filed 27 August 2026
How does O'Brien Investment Management get paid?
O'Brien Investment Management is paid through a percentage of assets under management. Its Form ADV lists no commissions or performance-based fees among how it is paid.
Source: Form ADV Part 1A, Item 5.E, from the SEC's 2 October 2026 data file
Is O'Brien Investment Management registered with the SEC?
Yes, O'Brien Investment Management has been registered with the SEC as an investment adviser since 24 March 2020. Its CRD number is 284057 and its SEC file number is 801-118289.
Source: Form ADV Part 1A, Item 1, filed 27 August 2026; IAPD firm record
How do I contact O'Brien Investment Management?
O'Brien Investment Management’s main office is at 24594 Hawthorne BLVD., Torrance, CA 90505. Its phone number is 310-363-2360. Its website is obrienim.com.