Shannon River Fund Management CO LLC

Hedge Fund • Long/Short

Shannon River Fund Management CO LLC is a Long/Short Hedge Fund based in New York, NY led by Spencer Marshal Waxman, reporting $844.7M in AUM as of Q3 2025 with 92% Technology concentration, 81% concentrated in top 10 holdings, and 92% technology allocation.

Managing PartnerSpencer Marshal Waxman

Portfolio Value: $621.2M
Positions: 20
Top Holding: PEGA at 12.81%
Last Reported: Q3 2025

Address850 Third Avenue, 13th Floor, New York, NY, 10022, United States

Top Holdings

Largest long holdings in Shannon River Fund Management CO LLC's portfolio (80.9% of total portfolio)

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Holding	Sector	Position	Weight	Traded	Ownership	Owned Since
1 Pegasystems PEGA	Software - Application Technology	$79.6M	12.81%	+$670.1K Bought	0.81% 1.4M shares	Q3 2024 Held for 1y 2m
2 Tower Semiconductor TSEM	Semiconductors Technology	$69.6M	11.20%	-$36.5M Sold	0.86% 962.1K shares	Q4 2023 Held for 1y 11m
3 InterDigital IDCC	Software - Application Technology	$61.7M	9.93%	-$20.0M Sold	0.69% 178.7K shares	Q2 2019 Held for 6y 5m
4 Wix.com WIX	Software - Infrastructure Technology	$58.6M	9.44%	+$17.4M Bought	0.59% 330.1K shares	Q3 2023 Held for 2y 2m
5 Flex Ltd. FLEX	Hardware, Equipment & Parts Technology	$49.2M	7.93%	-$26.2M Sold	0.23% 849.4K shares	Q3 2019 Held for 6y 2m
6 nCino, Inc. NCNO	Software - Application Technology	$42.8M	6.89%	+$9.2M Bought	1.36% 1.6M shares	Q2 2025 Held for 5 months
7 JFrog Ltd. FROG	Software - Application Technology	$40.9M	6.58%	+$30.6M Bought	0.74% 863.9K shares	Q2 2025 Held for 5 months
8 Marvell Technology, Inc. MRVL	Semiconductors Technology	$35.6M	5.73%	-$24.1M Sold	0.05% 423.6K shares	Q2 2024 Held for 1y 5m
9 FormFactor FORM	Semiconductors Technology	$35.3M	5.68%	+$35.3M New	1.26% 968.2K shares	Q3 2025 Held for 2 months
10 Guidewire Software GWRE	Software - Application Technology	$29.0M	4.66%	-$5.7M Sold	0.15% 126.1K shares	Q1 2024 Held for 1y 8m

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Changes

Portfolio activity, position movements, and quarter-over-quarter changes in Shannon River Fund Management CO LLC's latest filing

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Market Value

$621.2M

Prior: $645.0M

Q/Q Change

-3.69%

-$23.8M

Net Flows % of MV

-24.95%

Turnover Ratio

34.79%

New Purchases

5 stocks

$76.5M

Added To

5 stocks

+$58.1M

Sold Out Of

8 stocks

$105.8M

Reduced Holdings

9 stocks

-$183.8M

Increased Positions

Position	Shares Δ	Change
1 FormFactor FORM	New	0 → 968.2K +$35.3M
2 Clean Harbors CLH	New	0 → 115.9K +$26.9M
3 CCC CCC Intelligent Solutions Holdings Inc. CCC	New	0 → 1.1M +$9.8M
4 Taiwan Semiconductor Manufacturing Company TSM	New	0 → 8.7K +$2.4M
5 Backblaze, Inc. BLZE	New	0 → 229.4K +$2.1M

Decreased Positions

Position	Shares Δ	Change
1 Affirm Holdings, Inc. AFRM	Sold	356.6K → 0 −$24.7M
2 Maplebear Inc. CART	Sold	454.0K → 0 −$20.5M
3 Elastic ESTC	Sold	184.4K → 0 −$15.5M
4 Mirion Technologies MIR	Sold	555.4K → 0 −$12.0M
5 CCC Intelligent Solutions Holdings Inc. CCCS	Sold	1.1M → 0 −$10.1M