Top Institutional Investors

Great Diamond Partners, LLC — 13F Holdings & Portfolio

CIK 1801112 · latest 13F-HR filed 2026-10-13

Backtest portfolio

Great Diamond Partners, LLC manages $595.5M in 13F-reported U.S. long-equity assets across 238 reported positions as of its 2026-09-30 13F-HR filing. Its largest disclosed positions are VTI (5.54%), IWV (5.19%), IEFA (4.66%). Quarter over quarter (versus its 2026-06-30 filing) the fund opened 23 new positions and exited 23; 63 existing positions rose in reported value and 76 fell.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

Loading holdings…
AUM
$595.5M

Long-equity book

Holdings
238

Distinct positions

Period
2026-09-30

Filed 2026-10-13

Q/Q Activity
+23 / −23 / ↑63 / ↓76

vs 2026-06-30

Portfolio charts

Latest quarter's book, what changed, and how the portfolio has evolved across filings.

Portfolio map

Q3 26
VTI5.5% · +0%IWV5.2% · -1%IEFA4.7% · +1%VXF2.4% · -1%MSFT2.3% · -1%AVEM2.1% · +1%AGGH2.1% · +9%DFAI1.9% · +3%PG1.9% · -0%IBDS1.7% · newDYNF1.6% · +15%RSP1.6% · +47%AAPL1.6% · +1%PYLD1.5% · +8%VUG1.5% · -1%AGZ1.4% · +4%NVDA1.3% · -2%IBDU1.3% · +45%IDXX1.3% · +1%IEI1.2% · +7%IJH1.2% · +6%AVGO1.1% · -0%IBDT1.0% · +53%GOOGL1.0% · -2%KLAC1.0% · +2%HGER1.0% · -43%GOOG0.9% · +0%XOM0.9% · newWSM0.9% · +1%TSM0.8% · +3%WELL0.8% · -0%WM0.7% · +1%CAH0.7% · +1%AMGN0.7% · -0%LLY0.7% · -1%BNY0.7% · newAMZN0.7% · +0%GLW0.7% · -12%PH0.7% · +1%JPM0.6% · -0%VLO0.6% · -1%CAT0.6% · +4%SPHY0.6% · +5%EMB0.6% · +4%SJNK0.6% · +6%IGIB0.6% · +6%IDNA0.5% · newGRMN0.5% · -0%UNM0.5% · +0%AU0.5% · -12%XBI0.5% · +3%AIQ0.5% · +3%TDIV0.5% · -1%SKYY0.5% · newADP0.5% · -1%BLK0.5% · -2%DTCR0.5% · +3%QTUM0.5% · +4%SMH0.5% · -5%XTL0.5% · +4%

Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.

Sector mix

% of 13F value

Sectors from each company's SIC code; funds and ETFs grouped separately.

Biggest buys and sells

Q2 26 → Q3 26

Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.

13F assets and positions

5 quarters

Total reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.

Top positions over time

reported value

The eight largest current positions, valued at each quarter end.

Concentration

top 10 = 29.9%

Cumulative share of the portfolio held in the largest N positions.

Firm Profile & Key People

As of the firm’s regulatory filing dated Sep 14, 2026.

Assets Under Management
$804.1M
Discretionary
$804.1M
Employees
12
Accounts
1,736
Address
22 MONUMENT SQUARE
SUITE 300
PORTLAND, ME 04101
Phone
(207) 274-2500
Website
Name Title / Status Ownership Type
ANDREOLI, HELEN, ELIZABETH ControlMANAGING PARTNER/CHIEF FINANCIAL OFFICER
since Apr 2026
25–50%Individual
PIPER, JOHN, MARSHALL ControlFOUNDING PARTNER/PORTFOLIO MANAGER/CHIEF COMPLIANCE OFFICER
since Apr 2026
10–25%Individual
POWERS, JOSEPH, WILLIAM ControlFOUNDING PARTNER/CHIEF PLANNING OFFICER
since May 2019
25–50%Individual
Ownership & leadership changes · 2 filings with changes since Mar 25, 2019

From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.

Apr 17, 2026 filing
  • No longer listedTENNEY, STEVEN, EDWARD · FOUNDING PARTNER/CHIEF EXECUTIVE OFFICER · 25–50% · control person · listed since May 2019
  • ChangedANDREOLI, HELEN, ELIZABETH · title FOUNDING PARTNER/CHIEF FINANCIAL OFFICER → MANAGING PARTNER/CHIEF FINANCIAL OFFICER; ownership 10–25% → 25–50%
  • ChangedPIPER, JOHN, MARSHALL · ownership 5–10% → 10–25%
May 9, 2019 filing
  • No longer listedKupfer, Corey, NMN · MANAGING MEMBER · 75% or more · indirect via RIAKA HOLDINGS, LLC · control person · listed since Mar 2019
  • No longer listedRIAKA HOLDINGS, LLC · DIRECT OWNER · 75% or more · control person · listed since Mar 2019
  • AddedANDREOLI, HELEN, ELIZABETH · FOUNDING PARTNER/CHIEF FINANCIAL OFFICER · 10–25% · control person
  • AddedPOWERS, JOSEPH, WILLIAM · FOUNDING PARTNER/CHIEF PLANNING OFFICER · 25–50% · control person
  • AddedTENNEY, STEVEN, EDWARD · FOUNDING PARTNER/CHIEF EXECUTIVE OFFICER · 25–50% · control person
  • ChangedPIPER, JOHN, MARSHALL · title CHIEF COMPLIANCE OFFICER → FOUNDING PARTNER/PORTFOLIO MANAGER/CHIEF COMPLIANCE OFFICER; ownership Less than 5% → 5–10%; now a control person
Mar 25, 2019 filing (earliest on record)
  • ListedKupfer, Corey, NMN · MANAGING MEMBER · 75% or more · indirect via RIAKA HOLDINGS, LLC · control person
  • ListedPIPER, JOHN, MARSHALL · CHIEF COMPLIANCE OFFICER · Less than 5%
  • ListedRIAKA HOLDINGS, LLC · DIRECT OWNER · 75% or more · control person

Quarter-over-quarter changes

Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.

Great Diamond Partners, LLC Holdings (2026-09-30)

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 VANGUARD INDEX FDS VTI 922908769 $33.0M 5.54% 88,142 SH
2 ISHARES TR IWV 464287689 $30.9M 5.19% 71,655 SH
3 ISHARES TR IEFA 46432F842 $27.8M 4.66% 286,681 SH
4 VANGUARD INDEX FDS VXF 922908652 $14.2M 2.38% 61,301 SH
5 MICROSOFT CORP MSFT 594918104 $14.0M 2.35% 27,270 SH
6 AMERICAN CENTY ETF TR AVEM 025072604 $12.7M 2.13% 135,236 SH
7 SIMPLIFY EXCHANGE TRADED FUN AGGH 82889N723 $12.4M 2.08% 655,437 SH
8 DIMENSIONAL ETF TRUST DFAI 25434V203 $11.6M 1.94% 279,518 SH
9 PROCTER & GAMBLE CO PG 742718109 $11.4M 1.92% 78,536 SH
10 ISHARES TR IBDS 46435UAA9 $10.2M 1.70% 420,932 PRN
11 BLACKROCK ETF TRUST DYNF 09290C103 $9.7M 1.63% 139,885 SH
12 INVESCO EXCHANGE TRADED FD T RSP 46137V357 $9.6M 1.61% 46,010 SH
13 APPLE INC AAPL 037833100 $9.3M 1.56% 27,826 SH
14 PIMCO ETF TR PYLD 72201R585 $8.8M 1.48% 347,235 SH
15 VANGUARD INDEX FDS VUG 922908736 $8.7M 1.47% 96,896 SH
16 ISHARES TR AGZ 464288166 $8.3M 1.39% 77,613 SH
17 NVIDIA CORPORATION NVDA 67066G104 $8.0M 1.34% 35,027 SH
18 ISHARES TR IBDU 46436E205 $7.8M 1.30% 341,592 SH
19 IDEXX LABS INC IDXX 45168D104 $7.5M 1.26% 14,421 SH
20 ISHARES TR IEI 464288661 $7.3M 1.23% 64,576 SH
21 ISHARES TR IJH 464287507 $7.1M 1.19% 98,254 SH
22 BROADCOM INC AVGO 11135F101 $6.6M 1.11% 18,899 SH
23 ISHARES TR IBDT 46435U515 $6.2M 1.04% 247,275 SH
24 ALPHABET INC GOOGL 02079K305 $6.1M 1.03% 17,822 SH
25 KLA CORP KLAC 482480100 $6.0M 1.00% 30,573 SH
26 HARBOR ETF TRUST HGER 41151J505 $5.7M 0.97% 163,064 SH
27 ALPHABET INC GOOG 02079K107 $5.4M 0.90% 15,800 SH
28 EXXONMOBIL HOLDINGS CORP XOM 30233Q108 $5.2M 0.88% 32,068 SH
29 WILLIAMS SONOMA INC WSM 969904101 $5.2M 0.87% 22,817 SH
30 TAIWAN SEMICONDUCTOR MANUFAC TSM 874039100 $4.8M 0.81% 10,622 SH
31 WELLTOWER INC WELL 95040Q104 $4.6M 0.77% 19,867 SH
32 WASTE MGMT INC DEL WM 94106L109 $4.4M 0.74% 21,748 SH
33 CARDINAL HEALTH INC CAH 14149Y108 $4.4M 0.74% 19,762 SH
34 AMGEN INC AMGN 031162100 $4.4M 0.73% 10,334 SH
35 ELI LILLY & CO LLY 532457108 $4.3M 0.72% 3,719 SH
36 BANK OF NY MELLON CORP BNY 064058100 $4.2M 0.71% 29,260 SH
37 AMAZON COM INC AMZN 023135106 $4.1M 0.68% 16,351 SH
38 CORNING INC GLW 219350105 $3.9M 0.66% 25,633 SH
39 PARKER-HANNIFIN CORP PH 701094104 $3.9M 0.66% 4,123 SH
40 JPMORGAN CHASE & CO JPM 46625H100 $3.8M 0.64% 11,565 SH
41 VALERO ENERGY CORP VLO 91913Y100 $3.7M 0.63% 9,637 SH
42 CATERPILLAR INC CAT 149123101 $3.6M 0.61% 4,464 SH
43 SPDR SERIES TRUST SPHY 78468R606 $3.6M 0.60% 158,805 SH
44 ISHARES TR EMB 464288281 $3.5M 0.58% 38,068 SH
45 SPDR SERIES TRUST SJNK 78468R408 $3.4M 0.58% 141,693 SH
46 ISHARES TR IGIB 464288638 $3.4M 0.57% 67,434 SH
47 ISHARES TR IDNA 46435U192 $3.2M 0.54% 76,558 SH
48 GARMIN LTD GRMN H2906T109 $3.2M 0.54% 11,274 SH
49 UNUM GROUP UNM 91529Y106 $3.2M 0.54% 36,700 SH
50 ANGLOGOLD ASHANTI PLC AU G0378L100 $3.2M 0.53% 33,763 SH
Filing History
Period Filed AUM Holdings Accession
2026-09-30 2026-10-13 $595.5M 238 0001172661-26-004501
2026-06-30 2026-07-17 $581.8M 238 0001172661-26-002658
2026-03-31 2026-05-12 $519.5M 228 0001172661-26-001739
2025-12-31 2026-02-06 $519.7M 227 0001172661-26-000514
2025-09-30 2025-10-20 $515.6M 225 0001172661-25-004336
Filer Information
Address
22 MONUMENT SQUARE
SUITE 300
PORTLAND, ME 04101
Phone
(207) 274-2500
Filing Manager
Great Diamond Partners, LLC
Portland, ME
Signatory
John M.Piper
Chief Compliance Officer