Sio Capital Management, Llc
- Regulatory AUM
- $1.3B
- Discretionary
- $1.3B
- Clients
- 6
- Avg AUM / client
- $216M
- Accounts
- 6
- Employees
- 13
AUM over time
Annual snapshots from Form ADV filings · as of Mar 18, 2026
Who they serve
| Client type | Clients | AUM | % of AUM |
|---|---|---|---|
| Pooled investment vehicles (non-investment companies) | 2 | $685M | 53.0% |
| Other investment advisers | 4 | $608M | 47.0% |
Private funds (2)
Reported in Form ADV Section 7.B.(1), filing of Mar 2024 · $710M combined gross assets
| Fund | Type | Domicile | Gross assets | Owners |
|---|---|---|---|---|
| Sio Partners, Lp | Hedge Fund | Delaware | $432M | 73 |
| Sio Partners Offshore, Ltd. | Hedge Fund | Cayman Islands | $278M | 35 |
People (3)
| Name | Role / title | Credentials | With firm since | Ownership |
|---|---|---|---|---|
| Castor, Michael, Bernard | Managing Member | Mar 2006 (20y) | 75% or more | |
| Drillick, Judah, Zvi | Chief Executive Officer | Jul 2015 (11y) | Less than 5% | |
| Lee, Jin, Woo | Chief Compliance Officer | Feb 2021 (6y) | Less than 5% |
Undisclosed: 0% – 25% of the firm is not attributable from the filed Schedule A bands.
Roster from the IAPD representatives feed; ownership and acquisition dates from Form ADV Schedule A/B. "Since" is the earliest filed registration or acquisition date.
Private funds (2, $710M gross assets)
| Fund | Type | Gross assets | Min. investment | Owners |
|---|---|---|---|---|
| Sio Partners, Lp | Hedge Fund | $432M | $1.0M | 73 |
| Sio Partners Offshore, Ltd. | Hedge Fund | $278M | $1.0M | 35 |
From Form ADV Section 7.B private fund reporting.
Documents (1 archived)
| Form | Period | Size | |
|---|---|---|---|
| Form ADV (full filing) | 03/18/2026 | 1.57 MB | View · PDF · Source ↗ |
Archived copies of the firm's regulatory filings, versioned by content hash.
Disciplinary disclosures
No disciplinary events reported on the firm's latest Form ADV filing.
How they charge
- • Percentage of assets under management
- • Performance-based fees
Services
- • Portfolio management for pooled investment vehicles
- • Portfolio management for businesses/institutional clients
Custody
Reported custodians
- Morgan Stanley $536M (41% of AUM) Mar 2026
- Goldman Sachs $104M (12% of AUM) Mar 2021
- Bnp Paribas Securities Corp. $61.1M (5% of AUM) Mar 2026
- Deutsche Bank Securities Inc. $34.1M (4% of AUM) Mar 2021
Amounts as reported in ADV Item 5.K.(3) (custodians holding 10%+ of SMA assets).
Firm reports it does not have custody of client funds or securities (Item 9.A).
Source
All data on this page comes from this firm's Form ADV filings, reproduced without modification. Latest filing: Mar 18, 2026.
View current Form ADV (SEC/IAPD) ↗