MAM
MASI

Montanaro Asset Management’s Masimo MASI Stock Holding History

Montanaro Asset Management’s Portfolio MASI Stock Details MASI Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2025
Q4 		– Sell
-12,960
Closed -$1.91M – 43
2025
Q3 		$1.91M Sell
12,960
-9,900
-43% -$1.5M 0.48% 41
2025
Q2 		$3.85M Sell
22,860
-9,440
-29% -$1.51M 0.99% 34
2025
Q1 		$5.38M Sell
32,300
-14,200
-31% -$2.46M 1.58% 27
2024
Q4 		$7.69M Sell
46,500
-9,200
-17% -$1.45M 1.59% 28
2024
Q3 		$7.43M Buy
55,700
+2,000
+4% +$232K 1.32% 31
2024
Q2 		$6.76M Sell
53,700
-53,400
-50% -$7.03M 1.26% 29
2024
Q1 		$15.7M Buy
107,100
+2,850
+3% +$368K 2.84% 15
2023
Q4 		$12.2M Sell
104,250
-38,000
-27% -$3.54M 2.3% 22
2023
Q3 		$12.5M Hold
142,250
– – 2.19% 24
2023
Q2 		$23.4M Buy
142,250
+8,500
+6% +$1.48M 3.7% 12
2023
Q1 		$24.7M Buy
133,750
+15,000
+13% +$2.53M 3.83% 10
2022
Q4 		$17.6M Buy
118,750
+2,250
+2% +$310K 2.86% 19
2022
Q3 		$16.4M Sell
116,500
-26,000
-18% -$3.8M 2.52% 21
2022
Q2 		$18.6M Buy
142,500
+12,500
+10% +$1.67M 2.8% 15
2022
Q1 		$18.9M Buy
130,000
+7,850
+6% +$1.51M 2.34% 19
2021
Q4 		$35.8M Buy
122,150
+19,200
+19% +$5.47M 3.61% 13
2021
Q3 		$27.9M Sell
102,950
-250
-0.2% -$67.8K 3.36% 15
2021
Q2 		$25M Sell
103,200
-1,300
-1% -$297K 3.15% 15
2021
Q1 		$24M Buy
104,500
+28,400
+37% +$7.13M 3.53% 11
2020
Q4 		$20.4M Buy
+76,100
New +$19M 3.44% 14

Other funds holding MASI

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
PCM
Politan Capital Management New York $985M AUM 3.12% 1-Year Est. Return
Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
Massachusetts Financial Services
Massachusetts Financial Services Boston, Massachusetts $298B AUM 21.96% 1-Year Est. Return
T. Rowe Price Investment Management
T. Rowe Price Investment Management Baltimore, Maryland $145B AUM 22.78% 1-Year Est. Return
NCMU
NAYA Capital Management (UK) London, United Kingdom $1.18B AUM 13.14% 1-Year Est. Return
Westfield Capital Management
Westfield Capital Management Boston, Massachusetts $23.8B AUM 49.45% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
Alyeska Investment Group
Alyeska Investment Group Chicago, Illinois $35.4B AUM 33.54% 1-Year Est. Return

Montanaro Asset Management's MASI Position: Q4 2025 in Review

Montanaro Asset Management sold out of Masimo (MASI) in Q4 2025, closing a stake of 12,960 shares — an estimated $1.91M sold.

Montanaro Asset Management first reported a position in MASI in Q4 2020 and held it in 20 quarters. The position peaked at $35.8M in Q4 2021. 390 funds tracked by Wall St. Rank hold MASI as of Q4 2025.

  • Montanaro Asset Management reported no remaining Masimo position as of Q4 2025 after selling out during the quarter.
  • Montanaro Asset Management sold 12,960 Masimo shares in Q4 2025, an estimated $1.91M.
  • Montanaro Asset Management first reported a position in Masimo in Q4 2020 and held it in 20 quarters.
  • Montanaro Asset Management's Masimo position peaked at $35.8M in Q4 2021.
  • 390 funds tracked by Wall St. Rank held Masimo as of Q4 2025.

Based on Montanaro Asset Management's 13F filing for Q4 2025, filed 10 Mar 2026.