Water Island Capital’s Penumbra PEN Stock Holding History

Water Island Capital’s Portfolio PEN Stock Details PEN Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$47.5M	Buy	150,456 +30,361	+25%	+$9.84M	4.42%	4
2026 Q1	$39.4M	Buy	+120,095	New	+$40.7M	4.4%	6

Other funds holding PEN

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

HBK Investments Dallas, Texas $10.2B AUM 67.73% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

ECM

ExodusPoint Capital Management New York $15.5B AUM 38.81% 1-Year Est. Return

Balyasny Asset Management Chicago, Illinois $80.2B AUM 51.53% 1-Year Est. Return

JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return

Goldman Sachs New York $1.15T AUM 47.82% 1-Year Est. Return

Arrowstreet Capital Boston, Massachusetts $225B AUM 49.49% 1-Year Est. Return

Water Island Capital's PEN Position: Q2 2026 in Review

Water Island Capital increased its Penumbra (PEN) stake by 25% in Q2 2026, buying an estimated $9.84M and bringing the position to 150,456 shares worth $47.5M. The position accounts for 4.42% of the portfolio, ranked #4.

Water Island Capital first reported a position in PEN in Q1 2026 and has held it in 2 quarters since. 451 funds tracked by Wall St. Rank hold PEN as of Q2 2026.

Water Island Capital held 150,456 shares of Penumbra worth $47.5M as of Q2 2026.
Water Island Capital bought 30,361 Penumbra shares in Q2 2026, an estimated $9.84M.
Penumbra made up 4.42% of Water Island Capital's portfolio in Q2 2026, its #4 holding.
Water Island Capital first reported a position in Penumbra in Q1 2026 and has held it in 2 quarters since.
451 funds tracked by Wall St. Rank held Penumbra as of Q2 2026.

Based on Water Island Capital's 13F filing for Q2 2026, filed 14 Aug 2026.