HI
MASI

HBK Investments’s Masimo MASI Stock Holding History

HBK Investments’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 		$458M Buy
+2,576,109
New +$404M 4.65% 6
2023
Q4 		– Sell
-295,000
Closed -$27.5M – 251
2023
Q3 		$25.9M Buy
+295,000
New +$34.3M 0.14% 38
2019
Q2 		– Sell
-28,173
Closed -$3.9M – 873
2019
Q1 		$3.9M Sell
28,173
-10,828
-28% -$1.36M 0.04% 378
2018
Q4 		$4.19M Buy
39,001
+11,893
+44% +$1.33M 0.04% 316
2018
Q3 		$3.38M Buy
27,108
+2,508
+10% +$278K 0.03% 386
2018
Q2 		$2.4M Sell
24,600
-40,901
-62% -$3.89M 0.02% 438
2018
Q1 		$5.76M Buy
65,501
+29,405
+81% +$2.56M 0.04% 238
2017
Q4 		$3.06M Sell
36,096
-42,350
-54% -$3.67M 0.02% 354
2017
Q3 		$6.79M Buy
78,446
+25,646
+49% +$2.27M 0.04% 215
2017
Q2 		$4.81M Buy
52,800
+40,600
+333% +$3.73M 0.03% 249
2017
Q1 		$1.14M Sell
12,200
-22,583
-65% -$1.86M 0.01% 402
2016
Q4 		$2.34M Sell
34,783
-38,417
-52% -$2.36M 0.02% 307
2016
Q3 		$4.36M Buy
73,200
+11,906
+19% +$672K 0.04% 240
2016
Q2 		$3.22M Buy
61,294
+37,061
+153% +$1.75M 0.02% 316
2016
Q1 		$1.01M Sell
24,233
-7,867
-25% -$296K 0.01% 586
2015
Q4 		$1.33M Buy
32,100
+16,700
+108% +$682K 0.01% 503
2015
Q3 		$594K Buy
+15,400
New +$629K 0.01% 711
2014
Q3 		– Sell
-21,700
Closed -$512K – 1024
2014
Q2 		$512K Buy
+21,700
New +$538K 0.01% 679

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
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
Millennium Management
Millennium Management New York $240B AUM 35.51% 1-Year Est. Return

HBK Investments's MASI Position: Q1 2026 in Review

HBK Investments opened a new position in Masimo (MASI) in Q1 2026: 2,576,109 shares worth $458M. The stake represents 4.65% of the portfolio and ranks #6 among its holdings. This is a return to the name: HBK Investments previously reported a position in MASI as recently as Q3 2023.

HBK Investments first reported a position in MASI in Q2 2014 and has held it in 18 quarters since. 445 funds tracked by Wall St. Rank hold MASI as of Q1 2026.

  • HBK Investments held 2,576,109 shares of Masimo worth $458M as of Q1 2026.
  • Masimo was a new HBK Investments position in Q1 2026.
  • Masimo made up 4.65% of HBK Investments's portfolio in Q1 2026, its #6 holding.
  • HBK Investments first reported a position in Masimo in Q2 2014 and has held it in 18 quarters since.
  • 445 funds tracked by Wall St. Rank held Masimo as of Q1 2026.

Based on HBK Investments's 13F filing for Q1 2026, filed 15 May 2026.