AltMountain

Mackay Shields LLC

New York, NY · CRD 107717
Hedge fund manager

Mackay Shields LLC is an SEC-registered investment adviser based in New York, NY that reports managing 14 hedge funds on Form ADV. It reports $159.5 billion in regulatory assets under management. Its private funds, of all types, hold $12.2 billion in gross assets. Its disclosed U.S. stock holdings returned an estimated +6.1% 2026 YTD through Jun 30 (S&P 500: +9.5%), based on 13F filings. Over a longer period they returned an estimated +15.1% from Q3 2024 to Q2 2026, compared with +37.2% for the S&P 500, based on 13F filings.

Regulatory assets under management
$159.5 billionForm ADV Item 5.F
Gross assets of private funds
$12.2 billionAll private fund types, Form ADV
Hedge funds managed
1416 private funds in total
Employees
206Form ADV Item 5.A
Registration
SEC-registered adviserCRD 107717
Latest Form ADV
08/06/2026Disciplinary disclosures: yes, see SEC record

Estimated 13F portfolio performance

Est. 2026 YTD+6.1%Through Q2 2026 · S&P 500 +9.5%
Est. 2-year return+15.1%Q3 2024 – Q2 2026
S&P 500+37.2%Same quarters, price only
13F holdings$813.1 million32 positions, 2026-06-30
$100$119$137Q3 2024Q1 2025Q3 2025Q1 202613F est. $115S&P 500 $137
QuarterEst. 13F returnS&P 500
Q2 2026+7.5%+14.8%
Q1 2026-1.3%-4.6%
Q4 2025+2.9%+2.4%
Q3 2025+3.6%+7.8%
Q2 2025+1.6%+10.4%
Q1 2025-1.8%-4.5%
Q4 2024-2.1%+2.1%
Q3 2024+4.2%+5.4%

Estimate of the firm's disclosed long U.S. stock portfolio from its quarterly 13F filings, holding each quarter-end portfolio to the next quarter-end at prices implied by all 13F filers. It is a price return before dividends and fees, ignores shorts, options, bonds, cash and trading within the quarter, and is not the return of any fund. Disclosures

Largest disclosed holdings

  • 02079k404$122.6 million
  • Hewlett Packard Enterprise C$70.2 million
  • Qxo Inc$57.4 million
  • Boeing Co$56.2 million
  • Nextera Energy Inc$50.5 million
  • Microchip Technology Inc.$46.5 million
  • Blackrock Mun Target Term TR$44.8 million
  • Apollo Global Mgmt Inc$43.5 million
  • 65441v200$39.2 million
  • 68389x204$29.1 million

As of 2026-06-30, from 13F filing by MacKay Shields LLC.

Hedge funds filing Form D (5)

Matched to this firm by the fund names and related persons in each Form D. The list may be incomplete.

Private funds reported on Form ADV (18)

Fund
Gross assets
Minimum
Owners
Adviser
Mackay Municipal Credit Opportunities Master Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$4.5B
Minimum$1.0M
Owners3,239
AdviserMackay Shields LLC
Mackay Municipal Opportunities Master Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$3.1B
Minimum$1.0M
Owners2,800
AdviserMackay Shields LLC
Mackay Municipal Opportunities Allocation Master Fund LP
Delaware, United StatesHedge fund
Gross assets$1.7B
Minimum$250K
Owners2,477
AdviserMackay Shields LLC
Mackay Municipal High Income Opportunities Fund LP
Delaware, United StatesHedge fund
Gross assets$669M
Minimum$250K
Owners998
AdviserMackay Shields LLC
Mackay Shields Intermediate Bond Fund LP
Delaware, United StatesHedge fund
Gross assets$647M
Minimum$1.0M
Owners4
AdviserMackay Shields LLC
Mackay Municipal High Yield Select Fund LP
Delaware, United StatesHedge fund
Gross assets$581M
Minimum$250K
Owners601
AdviserMackay Shields LLC
Mackay Municipal California Opportunities Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$566M
Minimum$250K
Owners447
AdviserMackay Shields LLC
Mackay Municipal Capital Trading Master Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$354M
Minimum$250K
Owners59
AdviserMackay Shields LLC
Mackay Shields High Yield Active Core Fund LP
Delaware, United StatesHedge fund
Gross assets$292M
Minimum$2.0M
Owners23
AdviserMackay Shields LLC
Mackay Municipal New York Opportunities Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$273M
Minimum$250K
Owners376
AdviserMackay Shields LLC
Mackay Shields Defensive Bond Arbitrage Fund LTD.
BermudaHedge fund
Gross assets$219M
Minimum$5.0M
Owners13
AdviserMackay Shields LLC
Mackay Shields Core Fixed Income Fund LP
Delaware, United StatesPrivate fund
Gross assets$157M
Minimum$1.0M
Owners8
AdviserMackay Shields LLC
Mackay Municipal Short Term Opportunities Fund LP
Delaware, United StatesHedge fund
Gross assets$112M
Minimum$250K
Owners33
AdviserMackay Shields LLC
Mackay Shields Core Plus/Opportunities Fund LP
Delaware, United StatesHedge fund
Gross assets$64.1M
Minimum$5.0M
Owners5
AdviserMackay Shields LLC
Mackay Municipal U.S. Infrastructure Opportunities Fund LP
Delaware, United StatesHedge fund
Gross assets$35.2M
Minimum$250K
Owners44
AdviserMackay Shields LLC
Mackay Shields Series Fund LLC - Structured Products Opportunities Series
Delaware, United StatesHedge fund
Gross assets$24.4M
Minimum$5.0M
Owners5
AdviserMackay Shields LLC
Mackay Municipal Strategic Opportunities Fund, L.P.
Delaware, United StatesHedge fund
Gross assets$1.6M
Minimum$500K
Owners260
AdviserMackay Shields LLC
Mackay Shields Select Credit Opportunities Fund LP
Delaware, United StatesHedge fund
Gross assets$360K
Minimum$1.0M
Owners2
AdviserMackay Shields LLC

As reported in the adviser's Form ADV filed Jul 2, 2024. Funds also listed from Form D are shown above.

From SEC filings. Firm data comes from the SEC's Form ADV data as of Oct 2, 2026; performance estimates come from Form 13F. AltMountain has not verified this information, and it is not an offer, solicitation or recommendation. Full disclosures