Great Diamond Partners, Llc
- Regulatory AUM
- $804M
- Discretionary
- $804M
- Clients
- 533
- Avg AUM / client
- $1.5M
- Accounts
- 1,736
- Employees
- 12
AUM over time
Annual snapshots from Form ADV filings · as of Apr 17, 2026
Investments (13F portfolio — 238 positions, $581,752,123)
13F period Jun 30, 2026| # | Issuer | Class | Value | Shares | % of 13F | % of AUM |
|---|---|---|---|---|---|---|
| 1 | Vanguard Index Fds | TOTAL STK MKT | $32,559,450 | 87,989 | 5.6% | 4.05% |
| 2 | Ishares Tr | RUSSELL 3000 ETF | $30,795,034 | 72,221 | 5.29% | 3.83% |
| 3 | Ishares Tr | CORE MSCI EAFE | $27,439,923 | 284,116 | 4.72% | 3.41% |
| 4 | Vanguard Index Fds | EXTEND MKT ETF | $15,196,081 | 61,720 | 2.61% | 1.89% |
| 5 | American Centy Etf Tr | AVANTIS EMGMKT | $12,880,643 | 133,492 | 2.21% | 1.6% |
| 6 | Simplify Exchange Traded Fun | AGGREGATE BD ETF | $12,175,381 | 603,638 | 2.09% | 1.51% |
| 7 | Procter & Gamble Co | COM | $11,558,018 | 78,819 | 1.99% | 1.44% |
| 8 | Dimensional Etf Trust | INTL CORE EQT MK | $11,236,500 | 272,400 | 1.93% | 1.4% |
| 9 | Microsoft Corp | COM | $10,294,013 | 27,596 | 1.77% | 1.28% |
| 10 | Kla Corp | COM NEW | $9,029,277 | 29,927 | 1.55% | 1.12% |
| 11 | Pimco Etf Tr | MULTISECTOR BD | $8,532,778 | 321,748 | 1.47% | 1.06% |
| 12 | Vanguard Index Fds | GROWTH ETF | $8,438,274 | 97,960 | 1.45% | 1.05% |
| 13 | Harbor Etf Trust | COMM ALL WEA ETF | $8,351,220 | 284,636 | 1.44% | 1.04% |
| 14 | Blackrock Etf Trust | ISHARES US EQUIT | $8,289,059 | 121,880 | 1.42% | 1.03% |
| 15 | Ishares Tr | AGENCY BOND ETF | $8,117,755 | 74,286 | 1.4% | 1.01% |
| 16 | Apple Inc | COM | $8,001,477 | 27,652 | 1.38% | 1.0% |
| 17 | Ishares Tr | IBONDS 27 ETF | $7,839,556 | 323,681 | 1.35% | 0.97% |
| 18 | Idexx Labs Inc | COM | $7,533,356 | 14,310 | 1.29% | 0.94% |
| 19 | Corning Inc | COM | $7,408,504 | 29,004 | 1.27% | 0.92% |
| 20 | Ishares Tr | CORE S&P MCP ETF | $7,163,133 | 92,895 | 1.23% | 0.89% |
| 21 | Broadcom Inc | COM | $7,156,565 | 18,945 | 1.23% | 0.89% |
| 22 | Nvidia Corporation | COM | $7,136,210 | 35,665 | 1.23% | 0.89% |
| 23 | Ishares Tr | 3 7 YR TREAS BD | $7,114,928 | 60,578 | 1.22% | 0.88% |
| 24 | Invesco Exchange Traded Fd T | S&P500 EQL WGT | $6,669,303 | 31,345 | 1.15% | 0.83% |
| 25 | Alphabet Inc | CAP STK CL A | $6,510,924 | 18,219 | 1.12% | 0.81% |
Top 25 of 238 positions from the manager's latest Form 13F · source filing (EDGAR) ↗. 13F covers long US-listed positions only. "% of AUM" is share of the firm's total regulatory AUM (Form ADV Item 5.F).
Who they serve
| Client type | Clients | AUM | % of AUM |
|---|---|---|---|
| Individuals (non-high net worth) | 238 | $73.8M | 9.18% |
| High net worth individuals | 285 | $716M | 89.0% |
| Pension and profit sharing plans | 7 | $11.8M | 1.47% |
| Charitable organizations | 3 | $2.5M | 0.31% |
People (9)
roster as of Jul 20, 2026| Name | Role / title | Credentials | With firm since | Ownership |
|---|---|---|---|---|
| Helen Elizabeth Andreoli | Founding Partner/Chief Financial Officer | CFP | May 2019 (7y) | 10% – 25% |
| John Marshall Piper | Founding Partner/Portfolio Manager/Chief Compliance Officer | May 2019 (7y) | 5% – 10% | |
| Joseph William Powers | Founding Partner/Chief Planning Officer | CFP | May 2019 (7y) | 25% – 50% |
| Tenney, Steven, Edward | Founding Partner/Chief Executive Officer | May 2019 (7y) | 25% – 50% | |
| Andrew Thomas Scott | Registered representative | CFP | Jun 2020 (6y) | |
| Wyatt Andreoli | Registered representative | Apr 2021 (5y) | ||
| Lisa Susan Demers | Registered representative | Jul 2021 (5y) | ||
| Stephen Daniel Poulos | Registered representative | May 2025 (1y) | ||
| Mark Oliver Doehla | Registered representative | Jul 2025 (1y) |
Undisclosed: 0% – 35% of the firm is not attributable from the filed Schedule A bands.
Roster from the IAPD representatives feed; ownership and acquisition dates from Form ADV Schedule A/B. "Since" is the earliest filed registration or acquisition date.
Documents (1 archived)
| Form | Period | Size | |
|---|---|---|---|
| Form ADV (full filing) | 04/17/2026 | 901 KB | View · PDF · Source ↗ |
Archived copies of the firm's regulatory filings, versioned by content hash.
Disciplinary disclosures
No disciplinary events reported on the firm's latest Form ADV filing.
How they charge
- • Percentage of assets under management
- • Hourly charges
- • Fixed fees
Services
- • Financial planning services
- • Portfolio management for individuals/small businesses
- • Other services
Custody
Reported custodians
- Charles Schwab & Co. $159M (20% of AUM) Apr 2026
Amounts as reported in ADV Item 5.K.(3) (custodians holding 10%+ of SMA assets).
Firm reports having custody of client funds or securities (Item 9.A).
Source
All data on this page comes from this firm's Form ADV filings, reproduced without modification. Latest filing: Apr 17, 2026.
View current Form ADV (SEC/IAPD) ↗