Investor Westfield Capital Management Co Lp
13D/G Filings

This page shows a list of all the recent 13D/G filings made by Westfield Capital Management Co Lp . Schedule 13D is commonly referred to as a “beneficial ownership report.” The term "beneficial owner" is defined under SEC rules. It includes any person who directly or indirectly shares voting power or investment power (the power to sell the security).

When a person or group of persons acquires beneficial ownership of more than 5% of a voting class of a company’s equity securities, they are required to file a Schedule 13D within ten days after the purchase. Click the link icon to see the full transaction history.

Add This Fund
to your dashboard

Date Form Target Prev
Shares		 Current
Shares		 Change
(Percent)		 Ownership
(Percent)		 Change
(Percent)
2026-06-03 13G/A IMAX / IMAX Corporation 2,704,872 2,737,381
2026-05-05 13G IMAX / IMAX Corporation 2,704,872
2026-03-04 13G/A BCYC / Bicycle Therapeutics plc - Depositary Receipt (Common Stock) 0 0
2026-03-03 13G/A BCYC / Bicycle Therapeutics plc - Depositary Receipt (Common Stock) 3,016,026 0
2026-03-03 13G/A BCYC / Bicycle Therapeutics plc - Depositary Receipt (Common Stock) 3,016,026 0
2026-02-11 13G/A ASND / Ascendis Pharma A/S 5,528,239 5,185,696
2026-02-11 13G/A BCYC / Bicycle Therapeutics plc - Depositary Receipt (Common Stock) 2,610,337 3,016,026
2025-03-05 13G/A FLYW / Flywire Corporation 6,516,044 0
2025-02-11 13G/A ASND / Ascendis Pharma A/S 5,528,239
2025-02-11 13G/A INVA / Innoviva, Inc. 4,106,136 0
2025-02-11 13G FLYW / Flywire Corporation 6,516,044
2025-02-11 13G BCYC / Bicycle Therapeutics plc - Depositary Receipt (Common Stock) 2,610,337
2025-02-10 13G/A ASND / Ascendis Pharma A/S 4,030,634 4,075,214
2024-08-05 13G/A MURA / Mural Oncology plc 743,495 0
2024-07-08 13G/A MURA / Mural Oncology plc 1,320,547 743,495
2024-05-08 13G/A MURA / Mural Oncology plc 1,548,418 1,320,547
2024-04-04 13G/A MURA / Mural Oncology plc 1,985,886 1,548,418
2024-02-02 13G/A ASND / Ascendis Pharma A/S 3,158,168 4,030,634
2024-01-10 13G MURA / Mural Oncology plc 1,985,886
2023-07-05 13G/A IRWD / Ironwood Pharmaceuticals, Inc. 8,145,674 0
2023-02-02 13G ASND / Ascendis Pharma A/S 3,158,168
2023-02-02 13G/A INVA / Innoviva, Inc. 3,683,485 4,106,136
2022-02-01 13G INVA / Innoviva, Inc. 3,683,485
2022-02-01 13G/A IRWD / Ironwood Pharmaceuticals, Inc. 8,488,042 8,145,674
2021-07-02 13G/A RUSHA / Rush Enterprises, Inc. 832,231 0
2021-02-01 13G/A SITM / SiTime Corporation 114,014 0
2021-01-07 13G/A SITM / SiTime Corporation 728,497 114,014
2021-01-07 13G IRWD / Ironwood Pharmaceuticals, Inc. 8,488,042
2020-01-07 13G SITM / SiTime Corporation 728,497
2020-01-07 13G/A CORV / Correvio Pharma Corp. (Canada) 4,894,685 0
2020-01-07 13G/A MDCO / Medicines Company 4,604,719 1,368,720
2019-09-04 13G/A CORV / Correvio Pharma Corp. (Canada) 4,788,032 4,894,685
2019-04-05 13G/A CORV / Correvio Pharma Corp. (Canada) 4,788,032
2019-02-07 13G MDCO / Medicines Company 4,604,719
2018-07-03 13G/A CORV / Correvio Pharma Corp. (Canada) 4,627,954
2018-07-03 13G/A CRME / Cardiome Pharma Corp. 4,149,244 4,627,954
2018-05-02 13G/A CRME / Cardiome Pharma Corp. 4,370,913 4,149,244
2018-03-02 13G/A CRME / Cardiome Pharma Corp. 4,758,844 4,370,913
2017-12-08 13G/A CRME / Cardiome Pharma Corp. 4,758,844 4,758,844
2017-12-07 13G/A CRME / Cardiome Pharma Corp. 4,931,969 4,758,844
2017-09-07 13G/A CRME / Cardiome Pharma Corp. 5,347,473 4,931,969
2017-08-08 13G/A CRME / Cardiome Pharma Corp. 5,078,393 5,347,473
2017-08-03 13G/A HXL / Hexcel Corporation 0
2017-04-10 13G/A HURN / Huron Consulting Group Inc. 0
2017-04-07 13G/A ARIA / ARIAD Pharmaceuticals, Inc. 4,957,058 0
2017-04-07 13G/A MACK / Merrimack Pharmaceuticals, Inc. 9,072,877 0
2017-02-10 13G/A RUSHA / Rush Enterprises, Inc. 1,629,607 832,231
2017-02-10 13G/A XPO / XPO, Inc. 0
2017-02-10 13G/A ARIA / ARIAD Pharmaceuticals, Inc. 9,493,458 4,957,058
2017-02-10 13G/A MACK / Merrimack Pharmaceuticals, Inc. 7,255,815 9,072,877
2017-02-10 13G/A CRME / Cardiome Pharma Corp. 5,423,142 5,078,393
2017-02-10 13G/A US00163U1060 / AMAG Pharmaceuticals, Inc. 1,827,052 0
2017-02-10 13G/A PTCT / PTC Therapeutics, Inc. 1,872,220 0
2017-02-10 13G/A SPNV / Supernova Partners Acquisition Company Inc - Class A 0
2016-09-09 13G/A CRME / Cardiome Pharma Corp. 3,955,392 5,423,142
2016-02-10 13G/A CRME / Cardiome Pharma Corp. 3,669,435 3,955,392
2016-02-10 13G PTCT / PTC Therapeutics, Inc. 1,872,220
2016-02-10 13G RUSHA / Rush Enterprises, Inc. 1,629,607
2016-02-10 13G MACK / Merrimack Pharmaceuticals, Inc. 7,255,815
2016-02-10 13G/A 98235T107 / Wright Medical Group N.V. 2,251,539
2016-02-10 13G US00163U1060 / AMAG Pharmaceuticals, Inc. 1,827,052
2016-02-10 13G ARIA / ARIAD Pharmaceuticals, Inc. 9,493,458
2016-02-05 13G/A MWIV / Mwi Veterinary Supply, Inc. 0
2016-02-05 13G/A AEGR / Aegerion Pharmaceuticals, Inc. 0
2016-02-05 13G/A DVAX / Dynavax Technologies Corporation 0
2015-11-09 13G/A CRME / Cardiome Pharma Corp. 3,222,395 3,669,435
2015-10-09 13G/A CRME / Cardiome Pharma Corp. 2,947,745 3,222,395
2015-08-07 13G/A CRME / Cardiome Pharma Corp. 2,753,510 2,947,745
2015-07-13 13G/A CRME / Cardiome Pharma Corp. 2,602,963 2,753,510
2015-06-09 13G/A CRME / Cardiome Pharma Corp. 2,236,577 2,602,963
2015-04-08 13G/A CRME / Cardiome Pharma Corp. 1,706,136 2,236,577
2015-03-06 13G/A CRME / Cardiome Pharma Corp. 1,706,136
2015-02-10 13G/A AEGR / Aegerion Pharmaceuticals, Inc. 2,755,933
2015-02-10 13G 98235T107 / Wright Medical Group N.V. 2,756,654
2015-02-10 13G MWIV / Mwi Veterinary Supply, Inc. 806,197
2015-02-10 13G DVAX / Dynavax Technologies Corporation 1,696,760
2015-02-10 13G CRME / Cardiome Pharma Corp. 1,521,187
2015-02-10 13G/A ARTC / Art Technology Acquisition Corp. 2,682,602
2015-02-10 13G/A NUAN / Nuance Communications Inc 0
2014-11-10 13G/A AEGR / Aegerion Pharmaceuticals, Inc. 2,532,824
2014-10-08 13G/A AEGR / Aegerion Pharmaceuticals, Inc. 3,475,306
2014-07-10 13G AEGR / Aegerion Pharmaceuticals, Inc. 3,207,598
2014-03-10 13G/A ARTC / Art Technology Acquisition Corp. 2,682,602
2014-02-07 13G/A ATMI / Atmi Inc 0
2014-02-07 13G/A XPO / XPO, Inc. 1,131,958
2014-02-07 13G/A HURN / Huron Consulting Group Inc. 715,516
2014-02-07 13G/A GLBR / Global Brokerage, Inc. 0
2014-02-07 13G/A TLYS / Tilly's, Inc. 0
2014-02-07 13G/A ELN / Elan Corp. Plc 0
2014-02-07 13G/A STEI / Stewart Enterprises Inc 0
2014-02-07 13G/A PMTI / Palomar Medical Technologies Llc 0
2014-02-07 13G/A OFIX / Orthofix Medical Inc. 0
2014-02-07 13G/A TWI / Titan International, Inc. 0
2014-02-07 13G/A US0153511094 / Alexion Pharmaceuticals, Inc. 0
2013-11-07 13G/A ARTC / Art Technology Acquisition Corp. 3,166,520
2013-05-06 13G/A ARTC / Art Technology Acquisition Corp. 2,963,976
2013-02-08 13G/A YTEN / Yield10 Bioscience, Inc. 0
2013-02-08 13G/A ATMI / Atmi Inc 759,576
2013-02-08 13G/A ARTC / Art Technology Acquisition Corp. 2,456,957
2013-02-08 13G/A 0
2013-02-08 13G XPO / XPO, Inc. 1,391,778
2013-02-08 13G HURN / Huron Consulting Group Inc. 1,312,279
2013-02-08 13G/A GLBR / Global Brokerage, Inc. 1,586,451
2013-02-08 13G TLYS / Tilly's, Inc. 520,042
2013-02-08 13G/A ANDV / Andeavor Corp. 6,110,929
2013-02-08 13G/A TWI / Titan International, Inc. 1,896,662
2012-03-27 13G/A ARTC / Art Technology Acquisition Corp. 1,894,335
2012-03-27 13G/A ATMI / Atmi Inc 1,808,458
2012-03-27 13G/A YTEN / Yield10 Bioscience, Inc. 2,696,628
2012-03-27 13G/A GLBR / Global Brokerage, Inc. 931,232
2012-03-27 13G/A ANDV / Andeavor Corp. 7,876,533
2012-03-27 13G/A STEI / Stewart Enterprises Inc 6,408,994
2012-03-27 13G/A OFIX / Orthofix Medical Inc. 632,337
2012-03-27 13G/A TWI / Titan International, Inc. 2,167,582
2012-02-13 13G/A ATMI / Atmi Inc 1,808,458
2012-02-13 13G/A HIBB / Hibbett, Inc. 0
2012-02-13 13G/A YTEN / Yield10 Bioscience, Inc. 2,696,628
2012-02-13 13G/A SNTS / Santarus, Inc 0
2012-02-13 13G ARTC / Art Technology Acquisition Corp. 1,894,335
2012-02-13 13G/A AROC / Archrock, Inc. 0
2012-02-13 13G GLBR / Global Brokerage, Inc. 931,232
2012-02-13 13G ANDV / Andeavor Corp. 7,876,533
2012-02-13 13G/A DNEX / Dionex Corp 0
2012-02-13 13G/A BLUD / Immucor Inc 0
2012-02-13 13G/A STEI / Stewart Enterprises Inc 6,408,994
2012-02-13 13G/A OFIX / Orthofix Medical Inc. 632,337
2012-02-13 13G TWI / Titan International, Inc. 2,167,582
2012-02-13 13G/A SUNH / Xuhang Holdings Limited 0