RDST Capital LLC

Hedge Fund • Long/Short

RDST Capital LLC is a Long/Short Hedge Fund based in Seattle, WA led by Brian David Pirie, managing $1.1B across 19 long positions as of Q3 2025 with 43% Technology concentration, 66% concentrated in top 10 holdings, and 43% technology allocation.

Managing PartnerBrian David Pirie

Portfolio Value: $1.1B
Positions: 19
Top Holding: ENTG at 8.33%
Last Reported: Q3 2025

Address1700 Westlake Ave N, Suite 200, Seattle, WA, 98109, United States

Top Holdings

Largest long holdings in RDST Capital LLC's portfolio (65.8% of total portfolio)

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Holding	Sector	Position	Weight	Traded	Ownership	Owned Since
1 Entegris ENTG	Semiconductors Technology	$88.5M	8.33%	-$13.5M Sold	0.63% 956.8K shares	Q4 2024 Held for 11 months
2 Union Pacific UNP	Railroads Industrials	$79.6M	7.49%	+$79.6M Bought	0.06% 336.6K shares	Q3 2025 Held for 2 months
3 Blue Owl Capital OWL	Asset Management Financial Services	$76.0M	7.16%	+$18.8M Bought	0.69% 4.5M shares	Q2 2023 Held for 2y 5m
4 Microsoft MSFT	Software - Infrastructure Technology	$72.7M	6.85%	-$9.3M Sold	0.00% 140.4K shares	Q4 2021 Held for 3y 11m
5 Martin Marietta Materials MLM	Construction Materials Basic Materials	$70.3M	6.62%	+$3.8M Bought	0.19% 111.6K shares	Q2 2025 Held for 5 months
6 Marvell Technology, Inc. MRVL	Semiconductors Technology	$69.4M	6.53%	+$32.9M Bought	0.10% 825.5K shares	Q3 2024 Held for 1y 2m
7 Datadog, Inc. DDOG	Software - Application Technology	$67.7M	6.37%	+$1.2M Bought	0.14% 475.1K shares	Q1 2025 Held for 8 months
8 Amazon AMZN	Specialty Retail Consumer Cyclical	$61.9M	5.83%	-$6.7M Sold	0.00% 281.8K shares	Q1 2023 Held for 2y 8m
9 HubSpot HUBS	Software - Application Technology	$56.8M	5.35%	+$56.8M New	0.23% 121.5K shares	Q3 2025 Held for 2 months
10 Floor & Decor FND	Home Improvement Consumer Cyclical	$55.8M	5.25%	+$6.4M Bought	0.70% 756.8K shares	Q2 2025 Held for 5 months

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Changes

Portfolio activity, position movements, and quarter-over-quarter changes in RDST Capital LLC's latest filing

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Market Value

$1.1B

Prior: $1.0B

Q/Q Change

+6.12%

+$61.3M

Net Flows % of MV

-6.43%

Turnover Ratio

22.09%

New Purchases

1 stocks

$56.8M

Added To

7 stocks

+$103.9M

Sold Out Of

1 stocks

$64.2M

Reduced Holdings

10 stocks

-$164.8M

Increased Positions

Position	Shares Δ	Change
1 HubSpot HUBS	New	0 → 121.5K +$56.8M
2 MarketAxess MKTX	+158.29%	109.0K → 281.5K +$30.1M
3 Marvell Technology, Inc. MRVL	+90.13%	434.2K → 825.5K +$32.9M
4 Meta Platforms, Inc. META	+40.16%	36.4K → 51.0K +$10.7M
5 Blue Owl Capital OWL	+32.82%	3.4M → 4.5M +$18.8M

Decreased Positions

Position	Shares Δ	Change
1 Restaurant Brands International QSR	Sold	968.1K → 0 −$64.2M
2 DoorDash DASH	-71.35%	169.6K → 48.6K −$32.9M
3 CSX CSX	-47.46%	2.9M → 1.5M −$48.7M
4 Applied Materials AMAT	-32.11%	384.7K → 261.1K −$25.3M
5 Carvana CVNA	-21.68%	136.9K → 107.2K −$11.2M