221b Master Fund LP

221b Master Fund LP is reported as a hedge fund in Form ADV private-fund disclosures. The adviser is 221b Capital Management LLC, based in Cayman Islands.

General hedge fund $25M to $100M $1M to $5M minimum

$33.7Mgross assets

$1.0Mminimum

4owners

3(c)(1)exemption

Disclosure fields

Fund facts

SEC private fund ID805-7837966351

Reference ID421488

JurisdictionCayman Islands

Fund of fundsNo

Master fundYes

Feeder fundNo

Non-US ownership0%

Assets valued100%

Annual auditYes

GAAPYes

Source periodMarch 2026

Date submitted03/25/2026

Adviser

221b Capital Management LLC

TypeExempt reporting adviser

SEC number802-130808

CRD329645

Regulatory AUM$33.7M

Compliance signals

Exempt from registration Sales limited Prime brokers reported Custodians reported

Service providers

Reported counterparties

General partners

221b Capital Partners LLC

Auditors

COHNREZNICK LLP

Prime brokers

GOLDMAN SACHS & CO. LLC

Custodians

GOLDMAN SACHS & CO. LLC

Administrators

STONE COAST FUND SERVICES LLC