Investor
MACKAY SHIELDS LLC
CIK 0000061227 · filed 2026-04-27 · SEC filing
13F book
$2.73B
Positions
111
7 new · 28 sold
Largest name
5.3%
Lumentum Hldgs Inc
Est. mark
$120.4M
Price effect on 104 names still held. Flow −$250.2M.
| Name | Ticker | Shares | Value | Weight | Est. mark | Change |
|---|---|---|---|---|---|---|
| Lumentum Hldgs Inc | — | 26.8M | $143.6M | 5.3% | $67.5M | Cut$58.2M |
| Western Digital Corp | WDC | 15.5M | $110.8M | 4.1% | $39.9M | Cut$24.2M |
| Advanced Energy Inds | — | 39.6M | $95.4M | 3.5% | $30.3M | Cut$22.1M |
| Mirum Pharmaceuticals, Inc. | MIRM | 23.1M | $69M | 2.5% | $9.38M | Cut$2.98M |
| Qxo Inc | — | 1.17M | $65.3M | 2.4% | $278.8K | Cut$234.5K |
| Lantheus Hldgs Inc | — | 50.9M | $61.2M | 2.2% | $2.77M | Cut−$3.9M |
| Mks Inc | MKSI | 36.5M | $60.4M | 2.2% | $13.7M | Cut$13.7M |
| Cable One, Inc. | CABO | 77.4M | $58.4M | 2.1% | −$4.29M | Added$1.72M |
| Tetra Tech Inc New | — | 54.5M | $57.2M | 2.1% | −$2.09M | Cut−$7.64M |
| Uber Technologies, Inc | UBER | 45.4M | $54.6M | 2.0% | −$4.06M | Added−$801.1K |
| Boeing Co | — | 829.4K | $53.9M | 2.0% | −$3.73M | Cut−$3.77M |
| On Semiconductor Corp | ON | 39.2M | $50.6M | 1.9% | $3.88M | Cut$3.63M |
| Pg&E Corp | — | 46.4M | $48.1M | 1.8% | $290.2K | Cut−$4.93M |
| Post Hldgs Inc | — | 40.2M | $43.6M | 1.6% | $241.7K | Cut−$9.77M |
| Integer Hldgs Corp | — | 45.2M | $43.3M | 1.6% | — | New |
| Apollo Global Mgmt Inc | — | 713.8K | $42M | 1.5% | −$11.9M | Cut−$11.9M |
| Liberty Media Corp Del | — | 34M | $39.3M | 1.4% | −$3.79M | Cut−$3.87M |
| Akamai Technologies Inc | AKAM | 33.8M | $39.2M | 1.4% | $5.28M | Cut$5.24M |
| Hewlett Packard Enterprise C | — | 601.9K | $39M | 1.4% | −$860.8K | Added−$602K |
| Snowflake Inc. | SNOW | 32.6M | $38.5M | 1.4% | −$9.08M | Added−$5.87M |
| Ncl Corp Ltd | — | 38.9M | $38M | 1.4% | −$913.9K | Held |
| BridgeBio Pharma, Inc. | BBIO | 33.3M | $37.4M | 1.4% | −$135.6K | Added$5.06M |
| Northern Oil & Gas, Inc. | NOG | 33.3M | $36.6M | 1.3% | $3.99M | Added$7.59M |
| Freshpet, Inc. | FRPT | 31.8M | $36.6M | 1.3% | −$441.1K | Added$11.6M |
| Irhythm Technologies Inc | IRTC | 32.6M | $35.8M | 1.3% | −$9.92M | Cut−$9.99M |
| Blackrock Mun Target Term Tr | — | 1.57M | $35.6M | 1.3% | −$163.7K | Added$4.42M |
| Chefs Whse Inc | — | 23.7M | $35.1M | 1.3% | −$1M | Cut−$1.06M |
| Ishares Gold Tr | — | 390.1K | $34.4M | 1.3% | $2.73M | Cut−$4.16M |
| Microchip Technology Inc. | — | 601K | $34.3M | 1.3% | −$797.4K | Cut−$822.3K |
| Burlington Stores, Inc. | BURL | 20.4M | $33.7M | 1.2% | $3.44M | Held |
| Patrick Inds Inc | — | 19.1M | $33.2M | 1.2% | $640.2K | Cut−$2.78M |
| Datadog, Inc. | DDOG | 33.8M | $32.8M | 1.2% | −$1.05M | Held |
| Fluor Corp | FLR | 26.3M | $32.5M | 1.2% | $2.45M | Added$2.47M |
| Live Nation Entertainment In | — | 29.7M | $32.1M | 1.2% | $801.5K | Added$857.7K |
| Etsy Inc | ETSY | 32.7M | $32M | 1.2% | −$1.13M | Cut−$5.49M |
| Seagate Hdd Cayman | — | 6.64M | $31.5M | 1.2% | $9.21M | Cut−$13.2M |
| Oracle Corp | — | 646.8K | $29.7M | 1.1% | — | New |
| Dexcom Inc | DXCM | 30M | $27.6M | 1.0% | $43.5K | Cut−$6.35M |
| Meritage Homes Corp | MTH | 28.1M | $27.2M | 1.0% | −$582.8K | Cut−$8.73M |
| Unity Software Inc. | U | 26.9M | $26.8M | 1.0% | — | New |
| Nutanix, Inc. | NTNX | 29.6M | $26.8M | 1.0% | −$1.85M | Added−$1.82M |
| Nextera Energy Inc | — | 472.9K | $26.7M | 1.0% | $2.18M | Added$2.72M |
| Peloton Interactive, Inc. | PTON | 19.4M | $26M | 1.0% | — | New |
| Parsons Corp Del | — | 26.1M | $25.8M | 0.9% | −$1.15M | Held |
| Biomarin Pharmaceutical Inc | BMRN | 26.5M | $25.6M | 0.9% | $121.5K | Cut−$7.71M |
| Progress Software Corp | — | 28.7M | $25.6M | 0.9% | −$3.53M | Added−$3.48M |
| Liberty Media Corp Del | — | 24.5M | $25.5M | 0.9% | $860.3K | Cut−$4.29M |
| Affirm Hldgs Inc | — | 27.1M | $25.5M | 0.9% | −$4.17M | Added−$1.45M |
| Nine Energy Service, Inc. | NINE | 3.07M | $25.1M | 0.9% | — | New |
| Guidewire Software, Inc. | GWRE | 25.1M | $25.1M | 0.9% | −$2.61M | Held |
| Bank America Corp | — | 20.9K | $24.9M | 0.9% | −$1.24M | Cut−$1.32M |
| Dropbox, Inc. | DBX | 24.3M | $23.1M | 0.8% | −$1.46M | Held |
| Blackrock Muniyield N Y Qual | — | 2.35M | $22.6M | 0.8% | −$364K | Added$10.9M |
| Blackrock Muniholdings Fd In | — | 1.98M | $22.4M | 0.8% | −$911.9K | Cut−$3.07M |
| Greenbrier Cos Inc | — | 19M | $22M | 0.8% | $1.53M | Held |
| Talos Energy Inc. | TALO | 1.33M | $20.9M | 0.8% | $6.3M | Cut−$12.2M |
| Gulfport Energy Corp | GPOR | 98.6K | $20.9M | 0.8% | $353K | Cut−$1.73M |
| Rivian Automotive Inc | — | 18.6M | $19.9M | 0.7% | −$3.46M | Added−$3.45M |
| Alnylam Pharmaceuticals, Inc. | ALNY | 14.8M | $19.1M | 0.7% | −$2.8M | Added−$2.79M |
| Shift4 Pmts Inc | — | 19.5M | $18.4M | 0.7% | −$434.6K | Cut−$19.7M |
| Upstart Hldgs Inc | — | 25.2M | $17.9M | 0.7% | −$4.12M | Held |
| Ares Management Corporation | — | 480K | $17.8M | 0.7% | −$6.36M | Added−$6.1M |
| Blackrock Muniyild Qult Fd I | — | 1.59M | $17.5M | 0.6% | −$114.5K | Added$13.5M |
| Wells Fargo Co New | — | 14.8K | $17.1M | 0.6% | −$826.9K | Cut−$839K |
| Synaptics Inc | SYNA | 16.2M | $16.8M | 0.6% | −$343.6K | Held |
| Jazz Investments I Ltd | — | 13.1M | $15.9M | 0.6% | $729.6K | Held |
| Workiva Inc | WK | 16.9M | $15.8M | 0.6% | −$850.9K | Held |
| Ionis Pharmaceuticals Inc | IONS | 10.4M | $15.7M | 0.6% | −$867.2K | Held |
| Lumentum Hldgs Inc | — | 2.2M | $15.6M | 0.6% | $7.39M | Cut−$2.24M |
| Cheesecake Factory Inc | CAKE | 15.4M | $15.2M | 0.6% | −$37.9K | Cut−$100.2K |
| Mgp Ingredients Inc New | — | 14.3M | $13.8M | 0.5% | −$79.6K | Added−$17K |
| BILL Holdings, Inc. | BILL | 15.1M | $13.5M | 0.5% | −$459.1K | Held |
| Blackrock Munihldgs Nj Qlty | — | 1.15M | $13.3M | 0.5% | −$378.8K | Cut−$1.39M |
| Q2 Hldgs Inc | — | 13.3M | $13.2M | 0.5% | −$227.1K | Cut−$12.6M |
| Aerovironment Inc | AVAV | 13.2M | $13M | 0.5% | −$1.09M | Added$1.86M |
| Global Pmts Inc | — | 12.9M | $11.4M | 0.4% | −$211.8K | Cut−$4.48M |
| Vertex, Inc. | VERX | 9.19M | $8M | 0.3% | −$729.5K | Cut−$9.22M |
| Spectrum Brands Inc | — | 7.86M | $7.86M | 0.3% | $410.9K | Held |
| Blackrock Muniyield Mich Qu | — | 659K | $7.83M | 0.3% | $92.3K | Cut$23.6K |
| Teladoc Health, Inc. | TDOC | 7.5M | $7.2M | 0.3% | $30K | Cut−$7.31M |
| Live Nation Entertainment In | — | 4.73M | $7.18M | 0.3% | $311.8K | Cut$220.3K |
| Osi Systems Inc | OSIS | 4.53M | $6.93M | 0.3% | $219.3K | Added$223.9K |
| Cloudflare, Inc. | NET | 5.68M | $6.65M | 0.2% | −$19K | Cut−$60.1K |
| Spdr Gold Tr | — | 15.3K | $6.6M | 0.2% | $521.1K | Held |
| Wec Energy Group, Inc. | WEC | 5.27M | $6.51M | 0.2% | $370.9K | Cut$291.5K |
| Neuberger Mun Fd Inc | — | 623.3K | $6.33M | 0.2% | $18.7K | Cut−$6.16M |
| Southern Co | — | 5.64M | $6.26M | 0.2% | $245.1K | Added$291.7K |
| Warner Bros. Discovery, Inc. | WBD | 226.3K | $6.21M | 0.2% | −$307.7K | Held |
| Halozyme Therapeutics, Inc. | HALO | 5.42M | $5.62M | 0.2% | −$212.8K | Added−$29.3K |
| Blackrock Muniyield Quality | — | 526.3K | $5.53M | 0.2% | — | New |
| Five9, Inc. | FIVN | 6.26M | $5.47M | 0.2% | −$187.9K | Cut−$6.09M |
| Nuveen New York Amt Qlt Muni | — | 519.9K | $5.31M | 0.2% | $62.4K | Cut−$1.16M |
| Nutanix, Inc. | NTNX | 4.6M | $4.69M | 0.2% | −$474.3K | Added−$403K |
| Integer Hldgs Corp | — | 3.85M | $4.54M | 0.2% | $206.8K | Added$347.3K |
| Abrdn Natl Mun Income Fd | — | 401.7K | $4M | 0.1% | −$124.5K | Held |
| Arrowhead Pharmaceuticals In | — | 3M | $3.11M | 0.1% | — | New |
| Invesco Tr Invt Grade Muns | — | 209.2K | $2.06M | 0.1% | −$104.6K | Cut−$1.14M |
| Invesco Municipal Trust | VKQ | 208.8K | $1.99M | 0.1% | −$27.1K | Cut−$1.15M |
| Mfs Mun Income Tr | — | 333.2K | $1.8M | 0.1% | −$13.3K | Cut−$48.6K |
| Blackrock Munihldngs Cali Ql | — | 146.8K | $1.53M | 0.1% | −$29.4K | Cut−$8.87M |
| Nuveen Pennsylvania Qlt Mun | — | 117.9K | $1.41M | 0.1% | $4.72K | Cut−$1.32M |
| Eaton Vance Mun Bd Fd | — | 125.8K | $1.23M | 0.0% | $5.03K | Cut−$1.87M |
| Invesco Mun Opportunity Tr | — | 126.3K | $1.2M | 0.0% | −$7.58K | Cut−$764.4K |
| Nuveen Municipal Credit Inc | — | 55.7K | $677.9K | 0.0% | −$22.3K | Cut−$3.4M |
| Blackline, Inc. | BL | 635K | $598.3K | 0.0% | −$73.1K | Held |
| Ppl Cap Fdg Inc | — | 500K | $586.4K | 0.0% | $37K | Held |
| Duke Energy Corp New | — | 500K | $551.8K | 0.0% | $36.1K | Held |
| Invesco Advantage Mun Income | — | 45.3K | $392.5K | 0.0% | −$20.8K | Cut−$572.1K |
| New York Life Invts Active E | — | 11.5K | $295.1K | 0.0% | −$914 | Added$8.53K |
| Ww Intl Inc | — | 14.4K | $197.5K | 0.0% | −$222.4K | Held |
| Chegg, Inc | CHGG | 45K | $43.4K | 0.0% | $3.22K | Held |
Positions as of Q1 2026. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.