MACKAY SHIELDS LLC — 13F Holdings & Portfolio
CIK 61227 · latest 13F-HR filed 2026-04-27
MACKAY SHIELDS LLC manages $2.73B in 13F-reported U.S. long-equity assets across 307 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are LITE (4.99%), WDC (3.32%), AEIS (2.93%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 7 new positions, exited 28, added to 23, and trimmed 53.
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.
$2.73B
Long-equity book
307
Distinct positions
2026-03-31
Filed 2026-04-27
+7 / −28 / ↑23 / ↓53
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- LUMENTUM HLDGS INC$58.2M +68.2%
- WESTERN DIGITAL CORP$24.2M +28.0%
- ADVANCED ENERGY INDS$22.1M +30.2%
- MKS INC.$13.7M +29.3%
- BLACKROCK MUNIYILD QULT FD I$13.5M +332.8%
Top Trims
- SHIFT4 PMTS INC-$19.7M -51.7%
- SEAGATE HDD CAYMAN-$13.2M -29.5%
- Q2 HLDGS INC-$12.6M -48.9%
- TALOS ENERGY INC-$12.2M -36.8%
- APOLLO GLOBAL MGMT INC-$11.9M -22.1%
New Positions
- INTEGER HLDGS CORP$43.3M
- ORACLE CORP$29.7M
- UNITY SOFTWARE INC$26.8M
- PELOTON INTERACTIVE INC$26.0M
- NINE ENERGY SERVICE INC$25.1M
Exited Positions
- FORD MTR CO$31.3M
- TYLER TEX INDPT SCH DIST$30.7M
- CABLE ONE INC$24.7M
- IMPINJ INC$16.1M
- BLACKROCK MUNIHLDGS NY QLTY$12.2M
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 | LUMENTUM HLDGS INC | LITE | 55024UAF6 | $136.2M | 4.99% | 25,408,000 | PRN |
| 2 | WESTERN DIGITAL CORP | WDC | 958102AT2 | $90.7M | 3.32% | 12,658,000 | PRN |
| 3 | ADVANCED ENERGY INDS | AEIS | 007973AE0 | $80.0M | 2.93% | 33,252,000 | PRN |
| 4 | MIRUM PHARMACEUTICALS INC | MIRM | 604749AB7 | $61.1M | 2.24% | 20,435,000 | PRN |
| 5 | QXO INC | QXOPB | 82846H504 | $56.6M | 2.08% | 1,013,696 | SH |
| 6 | MKS INC. | MKSI | 55306NAB0 | $53.2M | 1.95% | 32,168,000 | PRN |
| 7 | LANTHEUS HLDGS INC | LNTH | 516544AB9 | $52.0M | 1.91% | 43,266,000 | PRN |
| 8 | TETRA TECH INC NEW | TTEK | 88162GAB9 | $48.6M | 1.78% | 46,292,000 | PRN |
| 9 | BOEING CO | BAPA | 097023204 | $44.6M | 1.63% | 685,600 | SH |
| 10 | UBER TECHNOLOGIES INC | UBER | 90353TAM2 | $43.5M | 1.59% | 36,109,000 | PRN |
| 11 | ON SEMICONDUCTOR CORP | ON | 682189AS4 | $42.3M | 1.55% | 32,730,000 | PRN |
| 12 | INTEGER HLDGS CORP | ITGR | 45826HAD1 | $41.4M | 1.52% | 43,153,000 | PRN |
| 13 | PG&E CORP | PCG | 69331CAL2 | $39.2M | 1.44% | 37,877,000 | PRN |
| 14 | POST HLDGS INC | POST | 737446AT1 | $36.8M | 1.35% | 33,960,000 | PRN |
| 15 | NCL CORP LTD | NCLH | 62886HBD2 | $36.7M | 1.35% | 37,605,000 | PRN |
| 16 | CABLE ONE INC | CABO | 12685JAG0 | $35.2M | 1.29% | 46,630,000 | PRN |
| 17 | APOLLO GLOBAL MGMT INC | APOPA | 03769M304 | $35.2M | 1.29% | 597,400 | SH |
| 18 | ISHARES GOLD TR | IAU | 464285204 | $34.4M | 1.26% | 390,150 | SH |
| 19 | BRIDGEBIO PHARMA INC | BBIO | 10806XAD4 | $32.5M | 1.19% | 29,011,000 | PRN |
| 20 | BURLINGTON STORES INC | BURL | 122017AD8 | $32.4M | 1.19% | 19,605,000 | PRN |
| 21 | LIBERTY MEDIA CORP DEL | FWONA | 531229AQ5 | $32.4M | 1.19% | 28,022,000 | PRN |
| 22 | IRHYTHM HOLDINGS INC | IRTC | 450056AB2 | $32.4M | 1.19% | 29,518,000 | PRN |
| 23 | HEWLETT PACKARD ENTERPRISE C | HPEPC | 42824C208 | $32.0M | 1.17% | 492,700 | SH |
| 24 | DATADOG INC | DDOG | 23804LAD5 | $31.6M | 1.16% | 32,597,000 | PRN |
| 25 | AKAMAI TECHNOLOGIES INC | AKAM | 00971TAL5 | $31.3M | 1.15% | 26,957,000 | PRN |
| 26 | LIVE NATION ENTERTAINMENT IN | LYV | 538034BC2 | $30.8M | 1.13% | 28,500,000 | PRN |
| 27 | FRESHPET INC | FRPT | 358039AB1 | $30.3M | 1.11% | 26,288,000 | PRN |
| 28 | SEAGATE HDD CAYMAN | STX | 81180WBL4 | $30.2M | 1.11% | 6,350,000 | PRN |
| 29 | SNOWFLAKE INC | SNOW | 833445AB5 | $29.6M | 1.08% | 25,007,000 | PRN |
| 30 | PATRICK INDS INC | PATK | 703343AG8 | $28.5M | 1.04% | 16,420,000 | PRN |
| 31 | ETSY INC | ETSY | 29786AAJ5 | $27.9M | 1.02% | 28,509,000 | PRN |
| 32 | NORTHERN OIL & GAS INC | NOG | 665531AJ8 | $27.9M | 1.02% | 25,325,000 | PRN |
| 33 | MICROCHIP TECHNOLOGY INC. | MCHPP | 595017302 | $27.6M | 1.01% | 482,525 | SH |
| 34 | CHEFS WHSE INC | CHEF | 163086AE1 | $26.9M | 0.98% | 18,159,000 | PRN |
| 35 | NUTANIX INC | NTNX | 67059NAK4 | $25.6M | 0.94% | 28,260,000 | PRN |
| 36 | FLUOR CORP | FLR | 343412AJ1 | $25.4M | 0.93% | 20,591,000 | PRN |
| 37 | PARSONS CORP DEL | — | 70202LAD4 | $24.6M | 0.90% | 24,984,000 | PRN |
| 38 | LIBERTY MEDIA CORP DEL | FWONA | 531229AP7 | $24.3M | 0.89% | 23,328,000 | PRN |
| 39 | GUIDEWIRE SOFTWARE INC | GWRE | 40171VAC4 | $23.8M | 0.87% | 23,805,000 | PRN |
| 40 | CABLE ONE INC | CABO | 12685JAG0 | $22.9M | 0.84% | 30,394,000 | PRN |
| 41 | UNITY SOFTWARE INC | U | 91332UAH4 | $22.3M | 0.82% | 22,383,000 | PRN |
| 42 | PROGRESS SOFTWARE CORP | PRGS | 743312AD2 | $22.3M | 0.82% | 25,048,000 | PRN |
| 43 | ORACLE CORP | ORCLPD | 68389X204 | $22.0M | 0.81% | 476,535 | SH |
| 44 | DROPBOX INC | DBX | 26210CAD6 | $22.0M | 0.80% | 23,099,000 | PRN |
| 45 | AFFIRM HLDGS INC | AFRM | 00827BAD8 | $21.9M | 0.80% | 23,386,000 | PRN |
| 46 | GREENBRIER COS INC | GBX | 393657AM3 | $21.4M | 0.78% | 18,463,000 | PRN |
| 47 | BLACKROCK MUN TARGET TERM TR | BTT | 09257P105 | $21.3M | 0.78% | 936,793 | SH |
| 48 | DEXCOM INC | DXCM | 252131AM9 | $20.8M | 0.76% | 22,563,000 | PRN |
| 49 | PELOTON INTERACTIVE INC | PTON | 70614WAD2 | $20.7M | 0.76% | 15,455,000 | PRN |
| 50 | MERITAGE HOMES CORP | MTH | 59001ABF8 | $19.8M | 0.72% | 20,412,000 | PRN |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-04-27 | $2.73B | 307 | 0001085146-26-000371 |
| 2025-12-31 | 2026-01-29 | $2.86B | 340 | 0000061227-26-000001 |