RDST Capital LLC — 13F Holdings & Portfolio
CIK 1912187 · latest 13F-HR filed 2026-08-14
RDST Capital LLC manages $1.21B in 13F-reported U.S. long-equity assets across 18 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are JHX (8.70%), TSM (8.07%), MLM (7.81%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 2 new positions and exited 4; 10 existing positions rose in reported value and 5 fell.
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.
Long-equity book
Distinct positions
Filed 2026-08-14
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q2 26Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q1 26 → Q2 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
4 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 71%Cumulative share of the portfolio held in the largest N positions.
As of the firm’s regulatory filing dated May 1, 2026.
SUITE 200
SEATTLE, WA 98109
| Name | Title / Status | Ownership | Type |
|---|---|---|---|
| MASINO, KRISTEN, CARROLL Control | CHIEF OPERATING OFFICER AND CHIEF COMPLIANCE OFFICER since Jan 2026 | Less than 5% | Individual |
| PIRIE, BRIAN, DAVID Control | MANAGING MEMBER since Jul 2016 | 75% or more | Individual |
Ownership & leadership changes · 3 filings with changes since Dec 14, 2021
From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.
- No longer listedKalk, Yulia · CHIEF COMPLIANCE OFFICER · Less than 5% · listed since Sep 2025
- AddedMASINO, KRISTEN, CARROLL · CHIEF OPERATING OFFICER AND CHIEF COMPLIANCE OFFICER · Less than 5% · control person
- No longer listedHERNANDEZ, JAMES, RICHARD · CHIEF COMPLIANCE OFFICER & CHIEF OPERATING OFFICER · Less than 5% · control person · listed since Sep 2024
- AddedKalk, Yulia · CHIEF COMPLIANCE OFFICER · Less than 5%
- AddedHERNANDEZ, JAMES, RICHARD · CHIEF COMPLIANCE OFFICER & CHIEF OPERATING OFFICER · Less than 5% · control person
- ChangedPIRIE, BRIAN, DAVID · title MANAGING MEMBER AND CHIEF COMPLIANCE OFFICER → MANAGING MEMBER
- ListedPIRIE, BRIAN, DAVID · MANAGING MEMBER AND CHIEF COMPLIANCE OFFICER · 75% or more · control person
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- ARES MANAGEMENT CORPORATION$53.1M +151.5%
- FLOOR & DECOR HLDGS INC$53.0M +196.2%
- JAMES HARDIE INDS PLC$43.8M +71.4%
- MARTIN MARIETTA MATLS INC$38.3M +68.5%
- TAIWAN SEMICONDUCTOR MANUFAC$37.4M +62.3%
Top Trims
- DATADOG INC-$31.9M -45.3%
- MARKETAXESS HLDGS INC-$20.7M -42.4%
- CARVANA CO-$15.2M -27.6%
- APOLLO GLOBAL MGMT INC-$10.1M -43.3%
- MICROSOFT CORP-$4.4M -6.6%
Exited Positions
- BLUE OWL CAPITAL INC$69.8M
- MARVELL TECHNOLOGY INC$60.3M
- ENTEGRIS INC$41.9M
- SERVICENOW INC$8.0M
RDST Capital LLC Holdings (2026-06-30)
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 | JAMES HARDIE INDS PLC | JHX | G4253H101 | $105.1M | 8.70% | 4,015,067 | SH |
| 2 | TAIWAN SEMICONDUCTOR MANUFAC | TSM | 874039100 | $97.4M | 8.07% | 203,998 | SH |
| 3 | MARTIN MARIETTA MATLS INC | MLM | 573284106 | $94.3M | 7.81% | 163,550 | SH |
| 4 | UNION PAC CORP | UNP | 907818108 | $89.2M | 7.39% | 328,055 | SH |
| 5 | ARES MANAGEMENT CORPORATION | ARES | 03990B101 | $88.1M | 7.29% | 791,316 | SH |
| 6 | AMAZON COM INC | AMZN | 023135106 | $82.8M | 6.86% | 347,474 | SH |
| 7 | FLOOR & DECOR HLDGS INC | FND | 339750101 | $80.0M | 6.62% | 1,347,061 | SH |
| 8 | META PLATFORMS INC | META | 30303M102 | $79.2M | 6.56% | 140,667 | SH |
| 9 | DOORDASH INC | DASH | 25809K105 | $71.1M | 5.89% | 385,140 | SH |
| 10 | COUPANG INC | CPNG | 22266T109 | $70.1M | 5.80% | 4,034,829 | SH |
| 11 | NVIDIA CORPORATION | NVDA | 67066G104 | $65.8M | 5.45% | 328,839 | SH |
| 12 | MICROSOFT CORP | MSFT | 594918104 | $62.4M | 5.17% | 167,344 | SH |
| 13 | HUBSPOT INC | HUBS | 443573100 | $60.6M | 5.01% | 331,796 | SH |
| 14 | BROADCOM INC | AVGO | 11135F101 | $41.8M | 3.46% | 110,720 | SH |
| 15 | CARVANA CO | CVNA | 146869102 | $39.8M | 3.30% | 604,579 | SH |
| 16 | DATADOG INC | DDOG | 23804L103 | $38.5M | 3.19% | 148,040 | SH |
| 17 | MARKETAXESS HLDGS INC | MKTX | 57060D108 | $28.0M | 2.32% | 247,112 | SH |
| 18 | APOLLO GLOBAL MGMT INC | APO | 03769M106 | $13.3M | 1.10% | 112,385 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-14 | $1.21B | 18 | 0001912187-26-000007 |
| 2026-03-31 | 2026-05-15 | $1.04B | 20 | 0001912187-26-000005 |
| 2025-12-31 | 2026-02-17 | $1.06B | 19 | 0001420506-26-000500 |
| 2025-09-30 | 2025-11-18 | $1.06B | 19 | 0001420506-25-003460 |
SUITE 200
SEATTLE, WA 98109