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WESTFIELD CAPITAL MANAGEMENT CO LP: MASI position timeline

Available 13F reports, 13D and 13G stakes and each Form 3, 4 and 5 line of WESTFIELD CAPITAL MANAGEMENT CO LP on MASI, newest first. How the timeline and the estimate are built.

WESTFIELD CAPITAL MANAGEMENT CO LP held 0 MASI shares at 2026-06-30 per its 13F-HR filed 2026-08-12.

the latest 13F is the newest step

  1. period ended2026-06-30
    13F 0 shares
    Change vs previous 13F -341,229 shares

    13F-HR 0001177719-26-000021 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

    Exited: the 13F for this period no longer lists the position.

  2. period ended2026-03-31
    13F 341,229 shares
    Change vs previous 13F -1,180,820 shares

    0.25% of the 13F portfolio, value $60,694,349.

    13F-HR 0001177719-26-000018 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  3. period ended2025-12-31
    13F 1,522,049 shares
    Change vs previous 13F +102,799 shares

    0.82% of the 13F portfolio, value $197,957,646.

    13F-HR 0001177719-26-000005 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  4. period ended2025-09-30
    13F 1,419,250 shares
    Change vs previous 13F +238,047 shares

    0.88% of the 13F portfolio, value $209,410,274.

    13F-HR 0001177719-25-000003 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  5. period ended2025-06-30
    13F 1,181,203 shares
    Change vs previous 13F +509,724 shares

    0.83% of the 13F portfolio, value $198,702,016.

    13F-HR 0001085146-25-004820 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  6. period ended2025-03-31
    13F 671,479 shares
    Change vs previous 13F -97,379 shares

    0.54% of the 13F portfolio, value $111,868,445.

    13F-HR 0001085146-25-002864 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  7. period ended2024-12-31
    13F 768,858 shares
    Change vs previous 13F -625,198 shares

    0.55% of the 13F portfolio, value $127,092,256.

    13F-HR 0001085146-25-000986 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).

  8. period ended2024-09-30
    13F 1,394,056 shares
    Change vs previous 13F not available

    0.84% of the 13F portfolio, value $185,869,479.

    13F-HR 0001085146-24-005556 filed by WESTFIELD CAPITAL MANAGEMENT CO LP
    Filed (acceptance time not in the bulk data set), ingested

    Acceptance time not in the bulk data set (spec §4.2).