Jeremy Grantham's MASI Position Overview
Jeremy Grantham (via Grantham, Mayo, Van Otterloo & Co. LLC) currently holds 143,825 shares of Masimo Corporation (MASI) worth $18.71 M, representing 0.05% of the portfolio. First purchased in 2014-Q1, this medium-term investment has been held for 20 quarters.
Based on 13F filings, Jeremy Grantham has maintained a strategic position in MASI, demonstrating sustained confidence in this investment. Largest addition occurred in Q2 2025, adding 240,563 shares. Largest reduction occurred in Q4 2025, reducing 98,997 shares.
Analysis based on 13F filings available since 2013 Q2
Jeremy Grantham's Masimo Corporation (MASI) Holding Value Over Time
Track share changes against reported price movement
Quarterly Masimo Corporation (MASI) Trades by Jeremy Grantham
| Report Date | Bought/Sold (Sh.) | % Change | Qtr. End Shares | Reported Price |
|---|---|---|---|---|
| Q4 2025 | -98,997 | Reduce 40.77% | 143,825 | $130.06 |
| Q3 2025 | +2,259 | Add 0.94% | 242,822 | $147.55 |
| Q2 2025 | +240,563 | New Buy | 240,563 | $168.22 |
| Q2 2020 | -1,783 | Sold Out | 0 | $0.00 |
| Q1 2020 | -6,800 | Reduce 79.23% | 1,783 | $177.23 |
| Q4 2019 | -500 | Reduce 5.50% | 8,583 | $158.10 |
| Q3 2019 | +9,083 | New Buy | 9,083 | $148.74 |
| Q3 2017 | -2,300 | Sold Out | 0 | $0.00 |
| Q1 2017 | +2,300 | New Buy | 2,300 | $93.04 |
| Q2 2016 | -30,800 | Sold Out | 0 | $0.00 |
| Q1 2016 | -300 | Reduce 0.96% | 30,800 | $41.85 |
| Q4 2015 | -4,300 | Reduce 12.15% | 31,100 | $41.51 |
| Q2 2015 | -17,500 | Reduce 33.08% | 35,400 | $38.73 |
| Q1 2015 | -1,700 | Reduce 3.11% | 52,900 | $32.99 |
| Q4 2014 | -20,935 | Reduce 27.72% | 54,600 | $26.34 |
| Q3 2014 | -13,265 | Reduce 14.94% | 75,535 | $21.27 |
| Q2 2014 | +5,400 | Add 6.47% | 88,800 | $23.60 |
| Q1 2014 | +83,400 | New Buy | 83,400 | $27.31 |
Jeremy Grantham's Masimo Corporation Investment FAQs
Jeremy Grantham first purchased Masimo Corporation (MASI) in Q1 2014, acquiring 83,400 shares, as reported in their 13F filing for that period. Note: Analysis reflects filings available since Q2 2013; earlier records may be incomplete.
Jeremy Grantham has held Masimo Corporation (MASI) for 20 quarters since Q1 2014.
Jeremy Grantham's largest addition to Masimo Corporation (MASI) was in Q2 2025, adding 240,563 shares worth $40.47 M.
According to the latest 13F filing for Q4 2025, Jeremy Grantham's firm, Grantham, Mayo, Van Otterloo & Co. LLC, owns 143,825 shares of Masimo Corporation (MASI), valued at approximately $18.71 M.
As of the Q4 2025 filing, Masimo Corporation (MASI) represents approximately 0.05% of Jeremy Grantham's publicly disclosed stock portfolio, making it one of their key holdings.
Jeremy Grantham's peak holding in Masimo Corporation (MASI) was 242,822 shares, as reported at the end of Q3 2025.