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Super Investors / MacKay Shields LLC
MS

MacKay Shields LLC

Quarterly 13F snapshot: US-listed longs only, no performance figures — 13F data cannot support them.

Portfolio value
$2.99B
Positions
108
Quarter ended
June 30, 2026
Filed
July 28, 2026

Reported portfolio value by quarter (53 quarters reported)

$16.4B $1.81B
Q2 13 Q1 16 Q4 18 Q3 21 Q2 24 Q2 26

$1.88B in Q2 2013 → $2.99B now. Hover for any quarter.

Holdings

As reported for the quarter ended June 30, 2026. Activity is the change in share count since the prior quarter's filing.

Holding % of portfolio Activity Shares Value
Western Digital Corp 5.1% Trimmed 42% 8,952,000 $151M
Alphabet Inc 4.1% New 2,427,303 $123M
Mks Inc. 3.6% Trimmed 0.1% 36,470,000 $107M
LH Lumentum Hldgs Inc 2.8% Trimmed 52% 12,884,000 $84.1M
LH Lantheus Hldgs Inc 2.5% Trimmed 0.1% 50,863,000 $74M
HP Hewlett Packard Enterprise C 2.4% Trimmed 0.1% 601,263 $70.2M
Cable One Inc 2.0% Added 16% 89,888,000 $58.8M
Qxo Inc 1.9% Trimmed 0.1% 1,169,488 $57.4M
Boeing Co 1.9% Trimmed 0.1% 828,674 $56.2M
TT Tetra Tech Inc New 1.9% Trimmed 3.8% 52,445,000 $55.3M
Uber Technologies Inc 1.8% Added 0.0% 45,364,000 $54.3M
Snowflake Inc 1.8% Trimmed 0.1% 32,541,000 $54.2M
CW Chefs Whse Inc 1.8% Trimmed 0.2% 23,710,000 $53M
Etsy Inc 1.7% Added 52% 49,886,000 $50.9M
Nextera Energy Inc 1.7% Added 99% 940,950 $50.5M
PG&E Corp 1.6% Added 0.1% 46,453,000 $47.5M
Microchip Technology Inc. 1.6% Added 0.4% 603,491 $46.5M
BM Blackrock Mun Target Term Tr 1.5% Added 26% 1,967,980 $44.8M
IH Integer Hldgs Corp 1.5% Added 0.2% 45,243,000 $43.9M
AG Apollo Global Mgmt Inc 1.5% Trimmed 0.1% 713,153 $43.5M
LM Liberty Media Corp Del 1.4% Trimmed 0.2% 33,894,000 $42.1M
PH Post Hldgs Inc 1.4% Trimmed 0.2% 40,161,000 $41.7M
MM Merit Med Sys Inc 1.4% New 38,073,000 $41.1M
Akamai Technologies Inc 1.4% Added 0.6% 34,024,000 $40.8M
On Semiconductor Corp 1.3% Trimmed 44% 21,949,000 $40M
Nine Energy Service Inc 1.3% Trimmed 1.8% 3,011,565 $39.2M
Datadog Inc 1.3% Trimmed 19% 27,438,000 $39.1M
Revolution Medicines Inc 1.3% New 30,344,000 $38.1M
Freshpet Inc 1.2% Added 0.0% 31,800,000 $37M
Bridgebio Pharma Inc 1.2% Trimmed 0.2% 33,259,000 $36.9M
Irhythm Holdings Inc 1.2% Trimmed 0.1% 32,598,000 $35.9M
LN Live Nation Entertainment In 1.2% Unchanged 29,737,000 $35.6M
Peloton Interactive Inc 1.2% Added 11% 21,499,000 $34.9M
Fluor Corp 1.2% Trimmed 0.6% 26,167,000 $34.7M
JI Jazz Investments I Ltd 1.2% New 20,318,000 $34.7M
Northern Oil & Gas Inc 1.1% Trimmed 0.2% 33,241,000 $31.9M
AH Affirm Hldgs Inc 1.1% Trimmed 0.1% 27,113,000 $31.7M
Cyberark Software Ltd 1.1% New 19,004,000 $31.6M
Cloudflare Inc 1.1% New 24,872,000 $31.5M
Unity Software Inc 1.0% Added 0.0% 26,904,000 $30.5M
Oracle Corp 1.0% Trimmed 0.2% 645,801 $29.1M
Meritage Homes Corp 1.0% Trimmed 0.3% 28,031,000 $29M
PI Patrick Inds Inc 0.9% Trimmed 0.1% 19,118,000 $28.3M
LM Liberty Media Corp Del 0.9% Unchanged 24,458,000 $28.1M
Burlington Stores Inc 0.9% Trimmed 14% 17,529,000 $28M
PS Progress Software Corp 0.9% Trimmed 0.4% 28,590,000 $27.5M
BO Bank Of Amer Corp 0.9% Trimmed 0.3% 20,806 $26.1M
PD Parsons Corp Del 0.9% Added 0.1% 26,167,000 $25.8M
Biomarin Pharmaceutical Inc 0.9% Trimmed 0.3% 26,434,000 $25.7M
IG Ishares Gold Tr 0.8% Trimmed 16% 328,020 $24.8M
Dropbox Inc 0.8% Unchanged 24,323,000 $24.6M
AP Arrowhead Pharmaceuticals In 0.8% Added 582% 20,457,000 $24.5M
Doordash Inc 0.8% New 24,710,000 $24.4M
Synaptics Inc 0.8% Unchanged 16,169,000 $24M
Guidewire Software Inc 0.8% Trimmed 0.9% 24,911,000 $24M
BM Blackrock Muniyield N Y Qual 0.8% Unchanged 2,349,687 $23.8M
BM Blackrock Muniholdings Fd In 0.8% Unchanged 1,982,355 $23.6M
RA Rivian Automotive Inc 0.7% Trimmed 0.0% 18,580,000 $22.1M
GC Greenbrier Cos Inc 0.7% Unchanged 19,032,000 $21.8M
Dexcom Inc 0.7% Trimmed 25% 22,415,000 $20.9M

Showing top 60 of 108 positions.

Timeline of changes

What changed each quarter, from the filings' own share counts. Largest moves first; most recent 8 quarters.

Q2 2026

quarter ended June 30, 2026 · filed July 28, 2026

Company Action Shares changed Value of change % of portfolio
Alphabet Inc New +2,427,303 +$123M 4.1%
Western Digital Corp Trimmed −6,524,000 −$110M 5.1%
AE Advanced Energy Inds Trimmed −34,801,000 −$95M 0.4%
LH Lumentum Hldgs Inc Trimmed −13,902,000 −$90.8M 2.8%
Mirum Pharmaceuticals Inc Trimmed −21,107,000 −$78M 0.2%
MM Merit Med Sys Inc New +38,073,000 +$41.1M 1.4%
Revolution Medicines Inc New +30,344,000 +$38.1M 1.3%
N Ncl Corp Ltd Exited −38,891,000 −$38M
JI Jazz Investments I Ltd New +20,318,000 +$34.7M 1.2%
Cyberark Software Ltd New +19,004,000 +$31.6M 1.1%

Showing the 10 largest of 104 changes.

Q1 2026

quarter ended March 31, 2026 · filed April 27, 2026

Company Action Shares changed Value of change % of portfolio
IH Integer Hldgs Corp New +45,159,000 +$43.3M 1.6%
SH Seagate Hdd Cayman Trimmed −6,655,000 −$31.6M 1.2%
FM Ford Mtr Co Exited −30,093,000 −$31.3M
TT Tyler Tex Indpt Sch Dist Exited −30,319,000 −$30.7M
Oracle Corp New +646,846 +$29.7M 1.1%
Unity Software Inc New +26,902,000 +$26.8M 1.0%
Talos Energy Inc Trimmed −1,679,338 −$26.5M 0.8%
Peloton Interactive Inc New +19,417,000 +$26M 1.0%
Nine Energy Service Inc New +3,066,434 +$25.1M 0.9%
Cable One Inc Exited −24,975,000 −$24.7M

Showing the 10 largest of 117 changes.

Q4 2025

quarter ended December 31, 2025 · filed January 29, 2026

Company Action Shares changed Value of change % of portfolio
Halozyme Therapeutics Inc Trimmed −45,264,000 −$48.8M 0.2%
Osi Systems Inc Trimmed −28,014,000 −$41.5M 0.2%
SH Seagate Hdd Cayman Trimmed −12,275,000 −$41.3M 1.6%
Nutanix Inc Trimmed −36,136,000 −$40.6M 0.2%
Datadog Inc New +33,802,000 +$33.8M 1.2%
LN Live Nation Entertainment In New +29,685,000 +$31.3M 1.1%
Nutanix Inc New +29,610,000 +$28.6M 1.0%
Guidewire Software Inc New +25,147,000 +$27.7M 1.0%
Ionis Pharmaceuticals Inc Trimmed −17,383,000 −$27.7M 0.6%
AH Affirm Hldgs Inc New +24,259,000 +$26.9M 0.9%

Showing the 10 largest of 123 changes.

Q3 2025

quarter ended September 30, 2025 · filed October 27, 2025

Company Action Shares changed Value of change % of portfolio
Halozyme Therapeutics Inc New +50,503,000 +$58M 2.0%
Nice Ltd Exited −58,184,000 −$57.6M
Halozyme Therapeutics Inc Exited −43,628,000 −$49.8M
Nextera Energy Inc Exited −1,204,627 −$48M
Osi Systems Inc New +32,536,000 +$47.3M 1.6%
Snowflake Inc New +26,382,000 +$40.1M 1.4%
PR Permian Res Oper LLC Exited −14,774,000 −$35.8M
NA Nuveen Amt Free Qlty Mun Inc Trimmed −2,201,319 −$25.1M 0.7%
CI Chart Inds Inc Exited −400,972 −$24.4M
Freshpet Inc New +21,572,000 +$24.3M 0.8%

Showing the 10 largest of 118 changes.

Q2 2025

quarter ended June 30, 2025 · filed July 24, 2025

Company Action Shares changed Value of change % of portfolio
Nrg Energy Inc Exited −33,232,000 −$77.4M
Qxo Inc New +918,702 +$56.6M 1.8%
On Semiconductor Corp New +45,179,000 +$53.6M 1.7%
On Semiconductor Corp Exited −56,011,000 −$48.4M
Cloudflare Inc Trimmed −31,471,000 −$37.2M 0.2%
Mks Inc. New +37,307,000 +$36.9M 1.2%
Meritage Homes Corp New +37,250,000 +$36.2M 1.2%
Fluor Corp New +26,904,000 +$35.3M 1.1%
Dexcom Inc New +37,468,000 +$35.3M 1.1%
SA Southwest Airls Co Exited −33,931,000 −$33.9M

Showing the 10 largest of 106 changes.

Q1 2025

quarter ended March 31, 2025 · filed April 29, 2025

Company Action Shares changed Value of change % of portfolio
IH Integer Hldgs Corp Trimmed −38,079,000 −$55.5M 0.2%
Datadog Inc Exited −25,398,000 −$39.4M
Cloudflare Inc New +37,498,000 +$37.7M 1.2%
Enphase Energy Inc Exited −33,454,000 −$31.3M
SA Southwest Airls Co Trimmed −28,873,000 −$28.9M 1.1%
Booking Holdings Inc Trimmed −11,000,000 −$27.1M 0.9%
GP Global Pmts Inc New +27,430,000 +$26M 0.8%
Microchip Technology Inc. New +508,650 +$25.5M 0.8%
Kosmos Energy Ltd New +32,707,000 +$25.2M 0.8%
Euronet Worldwide Inc Exited −24,415,000 −$24.3M

Showing the 10 largest of 113 changes.

Q4 2024

quarter ended December 31, 2024 · filed February 04, 2025

Company Action Shares changed Value of change % of portfolio
Microchip Technology Inc. Exited −77,438,000 −$77.4M
Zillow Group Inc Exited −49,057,000 −$72.6M
PG&E Corp New +61,006,000 +$66.4M 2.0%
LH Lumentum Hldgs Inc Trimmed −54,846,000 −$60.2M 0.2%
LN Live Nation Entertainment In Trimmed −35,152,000 −$47.8M 0.2%
SP Shift4 Pmts Inc New +40,000,000 +$43.2M 1.3%
Uber Technologies Inc New +38,010,000 +$42M 1.2%
SP Shift4 Pmts Inc Trimmed −31,244,000 −$42M 0.2%
Boeing Co New +627,351 +$38.6M 1.1%
Envestnet Inc Exited −33,199,000 −$35.3M

Showing the 10 largest of 97 changes.

Q3 2024

quarter ended September 30, 2024 · filed October 31, 2024

Company Action Shares changed Value of change % of portfolio
TT Tetra Tech Inc New New +64,909,000 +$85.2M 2.3%
AP Amphastar Pharmaceuticals In New +40,950,000 +$43.4M 1.2%
SH Seagate Hdd Cayman New +30,110,000 +$43.4M 1.2%
Etsy Inc Exited −53,822,000 −$42.5M
AE Advanced Energy Inds New +40,132,000 +$42.4M 1.2%
Palo Alto Networks Inc Trimmed −11,639,000 −$40M 1.3%
TT Tyler Tex Indpt Sch Dist Added +30,018,000 +$37M 1.0%
Etsy Inc Added +34,419,000 +$34.1M 1.0%
Ionis Pharmaceuticals Inc New +30,793,000 +$32M 0.9%
Burlington Stores Inc New +20,561,000 +$29.1M 0.8%

Showing the 10 largest of 98 changes.

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