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Wellesley Asset Management — 13F Holdings & Portfolio

CIK 1533551 · latest 13F-HR filed 2026-08-13

Backtest portfolio

Wellesley Asset Management manages $1.10B in 13F-reported U.S. long-equity assets across 64 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are BOX (4.29%), ITRO (3.90%), BL (3.63%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 17 new positions and exited 7; 24 existing positions rose in reported value and 12 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
$1.10B

Long-equity book

Holdings
64

Distinct positions

Period
2026-06-30

Filed 2026-08-13

Q/Q Activity
+17 / −7 / ↑24 / ↓12

vs 2026-03-31

Portfolio charts

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

Portfolio map

Q2 26
BOX4.3% · -3%ITRO3.9% · +25%BL3.6% · +16%LIVN3.6% · +13%AVAV3.4% · +393%HAE3.3% · -1%SO3.2% · +670%MTH3.0% · -5%PCG3.0% · -5%GBX2.8% · -5%DASH2.7% · newPSN2.7% · +1%MCHP2.7% · -3%GWRE2.6% · -1%GPN2.4% · -8%DBX2.4% · +26%TVTX2.4% · newMMSI2.4% · newNVST2.3% · -1%AKAM2.3% · -54%RGEN2.2% · +4%WGO2.1% · -6%SYNA2.1% · -55%DDOG2.1% · -47%EEFT2.1% · newLMAT1.9% · +4%PRGS1.9% · -19%CMS1.9% · +53%OMCL1.9% · +9%USFD1.9% · newLNTH1.6% · -18%JD1.6% · newNTNX1.5% · +304%ON1.4% · -60%TTEK1.3% · +223%LYFT1.0% · -49%JAZZ0.9% · +36%WKC0.9% · +28%LYV0.9% · +89%PPL0.9% · -8%BMRN0.9% · +140%CAKE0.8% · +50%FLR0.7% · +82%LCII0.7% · -12%AMPH0.7% · -68%PCRX0.7% · +4%ETSY0.7% · newCOGT0.6% · +57%LNT0.5% · newALRM0.5% · -0%COLL0.4% · +39%POST0.4% · +44%CELC0.3% · newRVMDW0.3% · newNUVB0.2% · newIMCR0.2% · 0%BBIO0.0% · -18%UBER0.0% · newANIP0.0% · newFWONA0.0% · new

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

Q1 26 → Q2 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

3 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 = 34.1%

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

Firm Profile & Key People

As of the firm’s regulatory filing dated Mar 30, 2026.

Assets Under Management
$1.99B
Discretionary
$1.99B
Employees
30
Accounts
1,956
Address
100 MARKET STREET
SUITE 203
PORTSMOUTH, NH 03801
Phone
(781) 416-4000
Website
This firm reports 4 disclosure items on its registration.
Name Title / Status Ownership Type
BAILLIE, DAWN, MARIE ControlPRESIDENT
since Oct 2025
Less than 5%Individual
BUCKHAM, JAMES, WILLIAM ControlSENIOR PORTFOLIO MANAGER
since Dec 2025
Less than 5%Individual
CLOTT, DAVID, BRIAN ControlCHIEF INVESTMENT OFFICER
since Dec 2025
Less than 5%Individual
GODIN, DENNIS, P. ControlCHIEF OPERATING OFFICER
since Dec 2025
Less than 5%Individual
MILLER, GREG ControlFOUNDER
since Jul 1991
Less than 5%Individual
MILLER, MICHAEL, DAVID ControlCHIEF EXECUTIVE OFFICER / CO-TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2025
since Oct 2019
Less than 5%Individual
MULHERN, JAMES, PETER ControlCO-TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2025 / TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2020
since Oct 2025
Less than 5%Individual
RAWLINGS, STEVEN, GILBERT ControlCHIEF COMPLIANCE OFFICER AND GENERAL COUNSEL
since Oct 2025
Less than 5%Individual
HERNBERG, MAUREEN, PATRICIATRUSTEE OF THE DARLENE M. MURPHY TRUST - 2011
since Nov 2014
Less than 5%Individual
JOHNSON, SAMUEL, SLOANTRUSTEE OF THE MICHAEL DAVID MILLER TRUST - 2011
since Nov 2014
Less than 5%Individual
MURPHY, DARLENE, MARIEOWNER / SHAREHOLDER
since Oct 2019
5–10%Individual
THE DARLENE M. MURPHY TRUST - 2011OWNER / SHAREHOLDER
since Nov 2014
Less than 5%Domestic Entity
THE MICHAEL DAVID MILLER TRUST - 2011OWNER / SHAREHOLDER
since Nov 2014
5–10%Domestic Entity
THE MICHAEL MILLER IRREVOCABLE TRUST OF 2020OWNER / SHAREHOLDER
since Dec 2020
50–75%Domestic Entity
THE MICHAEL MILLER IRREVOCABLE TRUST OF 2025OWNER / SHAREHOLDER
since Jun 2025
10–25%Domestic Entity
Ownership & leadership changes · 21 filings with changes since Dec 22, 2011

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.

Mar 30, 2026 filing
  • No longer listedMARTINO, STEPHEN, DOMENIC · CHIEF FINANCIAL OFFICER · Less than 5% · control person · listed since Jan 2019
  • No longer listedMICHAEL MILLER IRREVOCABLE TRUST OF 2020 · OWNER / SHAREHOLDER · 50–75% · listed since Dec 2020
  • No longer listedMILLER, REGIS, C. · TRUSTEE OF THE GREG MILLER TRUST · Less than 5% · control person · listed since Jun 2016
  • No longer listedTHE GREG MILLER TRUST · OWNER/SHAREHOLDER · 10–25% · control person · listed since Jun 2016
  • No longer listedWilliam, Zorn · TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2020 · Less than 5% · listed since Dec 2020
  • AddedBUCKHAM, JAMES, WILLIAM · SENIOR PORTFOLIO MANAGER · Less than 5% · control person
  • AddedCLOTT, DAVID, BRIAN · CHIEF INVESTMENT OFFICER · Less than 5% · control person
  • AddedGODIN, DENNIS, P. · CHIEF OPERATING OFFICER · Less than 5% · control person
  • AddedMULHERN, JAMES, PETER · CO-TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2025 / TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2020 · Less than 5% · control person
  • AddedTHE MICHAEL MILLER IRREVOCABLE TRUST OF 2020 · OWNER / SHAREHOLDER · 50–75%
  • AddedTHE MICHAEL MILLER IRREVOCABLE TRUST OF 2025 · OWNER / SHAREHOLDER · 10–25%
  • ChangedMILLER, GREG · title FOUNDER, TRUSTEE OF THE GREG MILLER TRUST → FOUNDER
  • ChangedMILLER, MICHAEL, DAVID · title CEO → CHIEF EXECUTIVE OFFICER / CO-TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2025
  • ChangedMURPHY, DARLENE, MARIE · title OWNER/SHAREHOLDER → OWNER / SHAREHOLDER
  • ChangedRAWLINGS, STEVEN, GILBERT · title CCO AND GENERAL COUNSEL → CHIEF COMPLIANCE OFFICER AND GENERAL COUNSEL; now a control person
  • ChangedTHE DARLENE M. MURPHY TRUST - 2011 · ownership 5–10% → Less than 5%
Oct 29, 2025 filing
  • AddedRAWLINGS, STEVEN, GILBERT · CCO AND GENERAL COUNSEL · Less than 5%
  • ChangedBAILLIE, DAWN, MARIE · title CHIEF COMPLIANCE OFFICER → PRESIDENT
  • ChangedMILLER, MICHAEL, DAVID · title PRESIDENT AND CEO → CEO
Mar 28, 2025 filing
  • No longer listedMITCHELL, C. DANIEL · CHIEF OPERATING OFFICER · Less than 5% · control person · listed since Apr 2019
  • ChangedMICHAEL MILLER IRREVOCABLE TRUST OF 2020 · ownership 5–10% → 50–75%
  • ChangedMURPHY, DARLENE, MARIE · ownership 10–25% → 5–10%
  • ChangedTHE DARLENE M. MURPHY TRUST - 2011 · ownership 10–25% → 5–10%
  • ChangedTHE GREG MILLER TRUST · ownership 50–75% → 10–25%
  • ChangedTHE MICHAEL DAVID MILLER TRUST - 2011 · ownership 10–25% → 5–10%
Jul 10, 2024 filing
  • ChangedMILLER, GREG · title CHAIRMAN , CEO, TRUSTEE OF THE GREG MILLER TRUST → FOUNDER, TRUSTEE OF THE GREG MILLER TRUST
  • ChangedMILLER, MICHAEL, DAVID · title PRESIDENT AND CIO → PRESIDENT AND CEO
Sep 26, 2022 filing
  • AddedTHE GREG MILLER TRUST · OWNER/SHAREHOLDER · 50–75% · control person
  • ChangedMILLER, GREG · title CHAIRMAN AND CEO → CHAIRMAN , CEO, TRUSTEE OF THE GREG MILLER TRUST; ownership 50–75% → Less than 5%
  • ChangedMILLER, REGIS, C. · title OWNER / SHAREHOLDER → TRUSTEE OF THE GREG MILLER TRUST; ownership 50–75% → Less than 5%
  • ChangedMURPHY, DARLENE, MARIE · title OWNER → OWNER/SHAREHOLDER; ownership Less than 5% → 10–25%
Mar 22, 2022 filing
  • ChangedHERNBERG, MAUREEN, PATRICIA · ownership 10–25% → Less than 5%
  • ChangedJOHNSON, SAMUEL, SLOAN · ownership 10–25% → Less than 5%
  • ChangedMURPHY, DARLENE, MARIE · title DIRECTOR → OWNER; ownership 10–25% → Less than 5%; no longer a control person
  • ChangedWilliam, Zorn · ownership 5–10% → Less than 5%
Sep 7, 2021 filing
  • No longer listedSCHMIDT, CHARLES, B · CHIEF COMPLIANCE OFFICER · Less than 5% · control person · listed since Apr 2019
  • AddedBAILLIE, DAWN, MARIE · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
Mar 30, 2021 filing
  • AddedMICHAEL MILLER IRREVOCABLE TRUST OF 2020 · OWNER / SHAREHOLDER · 5–10%
  • AddedMILLER, REGIS, C. · OWNER / SHAREHOLDER · 50–75% · control person
  • AddedWilliam, Zorn · TRUSTEE OF THE MICHAEL MILLER IRREVOCABLE TRUST OF 2020 · 5–10%
  • ChangedMILLER, MICHAEL, DAVID · ownership 10–25% → Less than 5%
Jun 1, 2020 filing
  • ChangedMILLER, GREG · title CEO → CHAIRMAN AND CEO
Mar 27, 2020 filing
  • ChangedMURPHY, DARLENE, MARIE · title MANAGING DIRECTOR → DIRECTOR
Older changes (12 more filings)
Oct 14, 2019 filing
  • ChangedMILLER, MICHAEL, DAVID · title SENIOR VICE PRESIDENT AND CIO → PRESIDENT AND CIO
  • ChangedMURPHY, DARLENE, MARIE · title PRESIDENT → MANAGING DIRECTOR
Apr 24, 2019 filing
  • AddedSCHMIDT, CHARLES, B · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
  • ChangedMARTINO, STEPHEN, DOMENIC · title CFO → CHIEF FINANCIAL OFFICER
  • ChangedMITCHELL, C. DANIEL · title CCO/GENERAL COUNSEL → CHIEF OPERATING OFFICER
Jan 25, 2019 filing
  • No longer listedSAMUELS, PAUL, BURKE · TREASURER · Less than 5% · control person · listed since Jan 2015
  • AddedMARTINO, STEPHEN, DOMENIC · CFO · Less than 5% · control person
Sep 29, 2017 filing
  • ChangedMILLER, MICHAEL, DAVID · title SENIOR VICE PRESIDENT AND CO-CIO → SENIOR VICE PRESIDENT AND CIO
Mar 31, 2017 filing
  • ChangedMILLER, MICHAEL, DAVID · ownership Less than 5% → 10–25%
  • ChangedMITCHELL, C. DANIEL · title CCO → CCO/GENERAL COUNSEL
Aug 24, 2016 filing
  • No longer listedGROSSETTI, PAMELA, ANN · CHIEF COMPLIANCE OFFICER · Less than 5% · control person · listed since Jan 2015
  • AddedMITCHELL, C. DANIEL · CCO · Less than 5% · control person
Mar 31, 2015 filing
  • No longer listedGREG MILLER GRANTOR RETAINED ANNUITY TRUST · OWNER / SHAREHOLDER · 25–50% · control person · listed since Oct 2011
  • No longer listedGREG MILLER GRANTOR RETAINED ANNUITY TRUST · OWNER / SHAREHOLDER · 25–50% · indirect via GREG MILLER GRANTOR RETAINED ANNUITY TRUST · control person · listed since Oct 2011
  • AddedGROSSETTI, PAMELA, ANN · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
  • AddedHERNBERG, MAUREEN, PATRICIA · TRUSTEE OF THE DARLENE M. MURPHY TRUST - 2011 · 10–25%
  • AddedJOHNSON, SAMUEL, SLOAN · TRUSTEE OF THE MICHAEL DAVID MILLER TRUST - 2011 · 10–25%
  • AddedTHE DARLENE M. MURPHY TRUST - 2011 · OWNER / SHAREHOLDER · 10–25%
  • AddedTHE MICHAEL DAVID MILLER TRUST - 2011 · OWNER / SHAREHOLDER · 10–25%
  • ChangedSAMUELS, PAUL, BURKE · title CHIEF COMPLIANCE OFFICER → TREASURER
Apr 21, 2014 filing
  • AddedGREG MILLER GRANTOR RETAINED ANNUITY TRUST · OWNER / SHAREHOLDER · 25–50% · indirect via GREG MILLER GRANTOR RETAINED ANNUITY TRUST · control person
Mar 25, 2014 filing
  • ChangedMILLER, MICHAEL, DAVID · title SENIOR VICE PRESIDENT → SENIOR VICE PRESIDENT AND CO-CIO
Feb 26, 2014 filing
  • AddedGREG MILLER GRANTOR RETAINED ANNUITY TRUST · OWNER / SHAREHOLDER · 25–50% · control person
  • ChangedSAMUELS, PAUL, BURKE · title CHIEF COMPLIANCE OFFICER AND COO → CHIEF COMPLIANCE OFFICER
Mar 27, 2013 filing
  • ChangedMILLER, GREG · ownership 75% or more → 50–75%
Dec 22, 2011 filing (earliest on record)
  • ListedMILLER, GREG · CEO · 75% or more · control person
  • ListedMILLER, MICHAEL, DAVID · SENIOR VICE PRESIDENT · Less than 5% · control person
  • ListedMURPHY, DARLENE, MARIE · PRESIDENT · 10–25% · control person
  • ListedSAMUELS, PAUL, BURKE · CHIEF COMPLIANCE OFFICER AND COO · Less than 5% · 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.

Top Adds (vs prior quarter)

Show all 24 →

Top Trims

Show all 12 →

New Positions

Show all 17 →

Exited Positions

Show all 7 →

Wellesley Asset Management Holdings (2026-06-30)

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 BOX US BOX 10316TAD6 $47.0M 4.29% 49,546,000 PRN
2 ITRI US ITRO 465741AQ9 $42.7M 3.90% 44,985,000 PRN
3 BL US BL 09239BAF6 $39.8M 3.63% 42,867,000 PRN
4 LIVN US LIVN 53802LAB8 $39.0M 3.56% 31,146,000 PRN
5 AVAV US AVAV 008073AA6 $37.6M 3.43% 39,025,000 PRN
6 HAE US HAE 405024AD2 $36.6M 3.34% 37,883,000 PRN
7 MTH US MTH 59001ABF8 $33.2M 3.03% 32,281,000 PRN
8 PCG US PCG 69331CAL2 $32.8M 3.00% 32,230,000 PRN
9 GBX US GBX 393657AM3 $30.6M 2.80% 26,998,000 PRN
10 SO US SO 842587ED5 $30.2M 2.76% 30,127,000 PRN
11 DASH US DASH 25809KAB1 $30.0M 2.74% 31,902,000 PRN
12 PSN US PSN 70202LAD4 $29.9M 2.73% 30,098,000 PRN
13 MCHP US MCHP 595017BG8 $29.5M 2.70% 27,068,000 PRN
14 GWRE US GWRE 40171VAC4 $29.0M 2.65% 31,894,000 PRN
15 GPN US GPN 37940XAU6 $26.8M 2.45% 29,583,000 PRN
16 DBX US DBX 26210CAD6 $26.8M 2.45% 28,266,000 PRN
17 TVTX US TVTX 89422GAB3 $26.3M 2.40% 23,551,000 PRN
18 MMSI US MMSI 589889AB0 $26.1M 2.38% 25,627,000 PRN
19 NVST US NVST 29415FAD6 $25.3M 2.31% 25,263,000 PRN
20 RGEN US RGEN 759916AD1 $24.5M 2.24% 25,587,000 PRN
21 WGO US WGO 974637AF7 $23.4M 2.14% 24,881,000 PRN
22 SYNA US SYNA 87157DAJ8 $23.1M 2.11% 15,386,000 PRN
23 AKAM US AKAM 00971TAL5 $23.1M 2.11% 19,682,000 PRN
24 DDOG US DDOG 23804LAD5 $23.0M 2.10% 16,021,000 PRN
25 EEFT US EEFT 298736AM1 $22.7M 2.07% 27,000,000 PRN
26 LMAT US LMAT 525558AB8 $21.1M 1.92% 20,558,000 PRN
27 PRGS US PRGS 743312AD2 $20.9M 1.91% 21,041,000 PRN
28 CMS US CMS 125896BX7 $20.7M 1.89% 20,500,000 PRN
29 OMCL US OMCL 68213NAF6 $20.6M 1.88% 20,766,000 PRN
30 ITGR US — 45826HAD1 $20.5M 1.87% 21,186,000 PRN
31 LNTH US LNTH 516544AB9 $17.1M 1.56% 11,876,000 PRN
32 JD US JD 47215PAJ5 $17.0M 1.56% 17,185,000 PRN
33 NTNX US NTNX 67059NAK4 $16.0M 1.46% 16,171,000 PRN
34 ON US ON 682189AU9 $15.7M 1.43% 12,961,000 PRN
35 TTEK US TTEK 88162GAB9 $14.6M 1.33% 15,782,000 PRN
36 LYFT US LYFT 55087PAD6 $10.4M 0.95% 9,900,000 PRN
37 JAZZ US JAZZ 472145AH4 $10.1M 0.93% 7,500,000 PRN
38 WKC US WKC 98149GAB6 $10.0M 0.91% 9,170,000 PRN
39 LYV US LYV 538034BC2 $9.8M 0.90% 8,690,000 PRN
40 PPL US — 69352PAS2 $9.5M 0.87% 8,480,000 PRN
41 BMRN US BMRN 09061GAK7 $9.4M 0.86% 9,624,000 PRN
42 CAKE US CAKE 163072AC5 $8.9M 0.81% 9,000,000 PRN
43 FLR US FLR 343412AJ1 $8.0M 0.73% 7,645,000 PRN
44 LCII US LCII 501812AD3 $8.0M 0.73% 7,200,000 PRN
45 AMPH US AMPH 03209RAB9 $7.7M 0.70% 8,460,000 PRN
46 PCRX US PCRX 695127AJ9 $7.5M 0.69% 7,522,000 PRN
47 ETSY US ETSY 29786AAQ9 $7.1M 0.65% 7,735,000 PRN
48 COGT US COGT 19240QAA0 $6.5M 0.59% 7,250,000 PRN
49 LNT US LNT 018802AE8 $5.5M 0.50% 6,500,000 PRN
50 ALRM US ALRM 011642AD7 $5.4M 0.49% 5,626,000 PRN
Filing History
Period Filed AUM Holdings Accession
2026-06-30 2026-08-13 $1.10B 64 0001533551-26-000004
2026-03-31 2026-05-11 $952.5M 54 0001533551-26-000003
2025-12-31 2026-02-06 $960.8M 54 0001533551-26-000002
2025-12-31 2026-02-06 $672.2M 54 0001533551-26-000001
Filer Information
Address
100 MARKET STREET
SUITE 203
PORTSMOUTH, NH 03801
Phone
(781) 416-4000
Filing Manager
Wellesley Asset Management
PORTSMOUTH, NH
Signatory
Jim Buckham
Portfolio Manager