Reporting Owner Activity for SUMMIT PARTNERS L P

Form 3/4/5 issuer positions and transaction evidence for this reporting owner.

Issuer positions

Largest position

EngageSmart, Inc.

Disclosed value

$822.36M

Transaction activity

Available

Position snapshot: Estimated position value
$822.36M
Estimated from Forms 3/4/5 when filings include enough holding data.
Issuer positions
5
Distinct issuers connected to this reporting owner in parsed SEC filings.
Largest issuer position
EngageSmart, Inc.
$572.61M estimated from parsed reporting-owner filings.
Latest owner filing
05 Jan 2026
Most recent owner-level filing date in the parsed SEC record.
EngageSmart, Inc.
Estimated value: $572.61M · Role: 10%+ Owner
LifeStance Health Group, Inc. (LFST)
Estimated value: $169.97M · 12-month value change: -$42.63M · Role: 10%+ Owner
A10 Networks, Inc. (ATEN)
Estimated value: $68.48M · Role: 10%+ Owner
Solo Brands, Inc. (SBDS)
Estimated value: $10.9M · Role: 10%+ Owner
Klaviyo, Inc. (KVYO)
Estimated value: $388.3K · 12-month value change: -$485.2M · Role: 10%+ Owner
How to read Forms 3/4/5 positions
Reported values are estimates from parsed SEC Forms 3/4/5 when the filing includes enough price and share data.
Treat this as a filing-backed position snapshot, not as a live ownership feed.
Location: Boston, MA
Latest owner signature: /s/ Adam H. Hennessey, as attorney-in-fact for Summit Partners, L.P.
SEC filing history: Open SEC filing history

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