Jane Street
MASI

Jane Street’s Masimo MASI Stock Holding History

Jane Street’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
2026
Q1 		– Sell
-7,300
Closed -$949K – 12406
2025
Q4 		$949K Buy
7,300
+5,800
+387% +$831K ﹤0.01% 6233
2025
Q3 		$221K Buy
+1,500
New +$227K ﹤0.01% 9477
2024
Q4 		– Sell
-35,600
Closed -$4.75M – 10087
2024
Q3 		$4.75M Buy
35,600
+22,200
+166% +$2.58M ﹤0.01% 2945
2024
Q2 		$1.69M Sell
13,400
-2,000
-13% -$263K ﹤0.01% 4794
2024
Q1 		$2.26M Buy
15,400
+7,200
+88% +$930K ﹤0.01% 3914
2023
Q4 		$961K Sell
8,200
-40,000
-83% -$3.73M ﹤0.01% 5632
2023
Q3 		$4.23M Buy
48,200
+46,800
+3,343% +$5.45M ﹤0.01% 2855
2023
Q2 		$230K Sell
1,400
-200
-13% -$34.8K ﹤0.01% 7498
2023
Q1 		$295K Buy
+1,600
New +$270K ﹤0.01% 7226
2022
Q3 		– Sell
-2,300
Closed -$301K – 10131
2022
Q2 		$301K Buy
2,300
+700
+44% +$93.7K ﹤0.01% 7602
2022
Q1 		$233K Sell
1,600
-1,100
-41% -$211K ﹤0.01% 8803
2021
Q4 		$791K Buy
+2,700
New +$769K ﹤0.01% 6382
2021
Q3 		– Sell
-3,900
Closed -$946K – 10395
2021
Q2 		$946K Sell
3,900
-700
-15% -$160K ﹤0.01% 5959
2021
Q1 		$1.06M Sell
4,600
-5,800
-56% -$1.46M ﹤0.01% 5351
2020
Q4 		$2.79M Buy
10,400
+7,500
+259% +$1.87M ﹤0.01% 2917
2020
Q3 		$685K Sell
2,900
-13,500
-82% -$3.03M ﹤0.01% 4684
2020
Q2 		$3.74M Buy
+16,400
New +$3.6M ﹤0.01% 2210

Other funds holding MASI

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
PCM
Politan Capital Management New York $985M AUM 3.12% 1-Year Est. Return
PCM
Pentwater Capital Management Naples, Florida $19.3B AUM 58.13% 1-Year Est. Return
Barclays
Barclays London, United Kingdom $416B AUM 33.63% 1-Year Est. Return
HI
HBK Investments Dallas, Texas $9.85B AUM 55.6% 1-Year Est. Return
Massachusetts Financial Services
Massachusetts Financial Services Boston, Massachusetts $298B AUM 21.96% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Jane Street's MASI Position: Q1 2026 in Review

Jane Street reduced its Masimo (MASI) stake by 99% in Q1 2026, selling an estimated $16M and leaving 1,215 shares worth $216K. The position accounts for ﹤0.01% of the portfolio, ranked #9974.

Jane Street first reported a position in MASI in Q3 2013 and has held it in 36 quarters since. The position peaked at $18.2M in Q3 2022. 445 funds tracked by Wall St. Rank hold MASI as of Q1 2026.

  • Jane Street held 1,215 shares of Masimo worth $216K as of Q1 2026.
  • Jane Street sold 101,666 Masimo shares in Q1 2026, an estimated $16M.
  • Masimo made up ﹤0.01% of Jane Street's portfolio in Q1 2026, its #9974 holding.
  • Jane Street first reported a position in Masimo in Q3 2013 and has held it in 36 quarters since.
  • Jane Street's Masimo position peaked at $18.2M in Q3 2022.
  • 445 funds tracked by Wall St. Rank held Masimo as of Q1 2026.

Based on Jane Street's 13F filing for Q1 2026, filed 12 May 2026.