AltMountain

RA Capital Management, LP

Boston, MA · CRD 160174
Hedge fund manager

RA Capital Management, LP is an SEC-registered investment adviser based in Boston, MA that reports managing 1 hedge fund on Form ADV. It reports $16.4 billion in regulatory assets under management. Its private funds, of all types, hold $16.3 billion in gross assets. Its disclosed U.S. stock holdings returned an estimated +11.4% 2026 YTD through Jun 30 (S&P 500: +9.5%), based on 13F filings. Over a longer period they returned an estimated +46.3% from Q3 2024 to Q2 2026, compared with +37.2% for the S&P 500, based on 13F filings.

Regulatory assets under management
$16.4 billionForm ADV Item 5.F
Gross assets of private funds
$16.3 billionAll private fund types, Form ADV
Hedge funds managed
16 private funds in total
Employees
185Form ADV Item 5.A
Registration
SEC-registered adviserCRD 160174
Latest Form ADV
03/31/2026Disciplinary disclosures: none reported

Estimated 13F portfolio performance

Est. 2026 YTD+11.4%Through Q2 2026 · S&P 500 +9.5%
Est. 2-year return+46.3%Q3 2024 – Q2 2026
S&P 500+37.2%Same quarters, price only
13F holdings$11.5 billion84 positions, 2026-06-30
$77$112$146Q3 2024Q1 2025Q3 2025Q1 202613F est. $146S&P 500 $137
QuarterEst. 13F returnS&P 500
Q2 2026+14.7%+14.8%
Q1 2026-2.9%-4.6%
Q4 2025+19.3%+2.4%
Q3 2025+36.8%+7.8%
Q2 2025+4.6%+10.4%
Q1 2025-19.3%-4.5%
Q4 2024-15.3%+2.1%
Q3 2024+12.5%+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

  • K08588103$2.7 billion
  • 698955101$791.9 million
  • Rhythm Pharmaceuticals Inc$740.2 million
  • Vaxcyte Inc$667.0 million
  • Sionna Therapeutics Inc$435.7 million
  • Tyra Biosciences Inc$389.6 million
  • Edgewise Therapeutics Inc$341.0 million
  • Newamsterdam Pharma Company NV$323.7 million
  • 423494103$286.8 million
  • Septerna Inc$234.3 million

As of 2026-06-30, from 13F filing by RA Capital Management, L.P..

Hedge funds filing Form D (1)

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 (5)

Fund
Gross assets
Minimum
Owners
Adviser
RA Capital Healthcare Fund, LP
Delaware, United StatesHedge fund
Gross assets$9.4B
Minimum$2.0M
Owners1,046
AdviserRA Capital Management, LP
RA Capital Nexus III Fund, L.P.
Delaware, United StatesVenture capital fund
Gross assets$1.0B
Minimum$10.0M
Owners234
AdviserRA Capital Management, LP
RA Capital Nexus II Fund, L.P.
Delaware, United StatesVenture capital fund
Gross assets$430M
Minimum$10.0M
Owners196
AdviserRA Capital Management, LP
RA Capital Nexus Fund, L.P.
Delaware, United StatesVenture capital fund
Gross assets$309M
Minimum$10.0M
Owners95
AdviserRA Capital Management, LP
RA Capital Planetary Health Fund, LP
Delaware, United StatesVenture capital fund
Gross assets$62.2M
MinimumNone set
Owners17
AdviserRA Capital Management, LP

As reported in the adviser's Form ADV filed Mar 29, 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