Avidity Partners Management LP David Witzke

Dallas, TX 21 processed 13Fs on this site, 2021 Q3 to 2026 Q2

$624M
45 holdings
2026 Q2
+41.2% QoQ
Top 5 70.9%

Portfolio

2026 Q2, filed 8/14/2026, top 12 of 45 holdings

Top 5 70.9%, top 10 81.9%

AUM over time

2026 Q2 $624M +41.2% QoQ

Q3 2021

Q1 2022

Q1 2023

Q1 2024

Q1 2025

Q1 2026

Book

2021 Q4 2021 Q3, filed 14 Feb, long equity only

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ABBV, AbbVie	5.70%, was 3.86%	Add +23.0%	1,985,000	$135.40	$269M	+371,800	+$95M
ZNTL, Zentalis Pharmaceuticals	4.84%, was 3.68%	Add +8.9%	2,715,000	$84.06	$228M	+221,200	+$62M
ARVN, Arvinas	4.40%, was 4.07%	Add +13.1%	2,527,973	$82.14	$208M	+293,273	+$24M
AVTR, Avantor	4.28%, was 2.94%	Add +47.6%	4,792,000	$42.14	$202M	+1,544,300	+$69M
AZNN	3.54%, was 1.88%	Add +103.1%	2,867,200	$58.25	$167M	+1,455,200	+$82M
BHVN, Biohaven	3.33%, was 2.88%	Add +22.0%	1,140,000	$137.81	$157M	+205,800	+$27M
BAX, Baxter International	3.21%, was 1.54%	Add +104.8%	1,765,000	$85.84	$152M	+903,000	+$82M
ELV, Anthem	3.16%	New	321,000	$463.54	$149M	+321,000	+$149M
PFE, Pfizer	2.62%, was 0.98%	Add +103.5%	2,090,000	$59.05	$123M	+1,063,200	+$79M
Mirati Therapeutics	2.51%, was 4.16%	Reduce −24.1%	806,400	$146.69	$118M	−256,000	−$70M
Iveric Bio	2.47%, was 1.48%	Add +69.6%	6,955,000	$16.72	$116M	+2,855,000	+$50M
UTHR, United Therapeutics	2.45%, was 1.44%	Add +52.4%	535,000	$216.08	$116M	+184,000	+$51M
Arena Pharmaceuticals	2.40%, was 1.50%	Add +6.7%	1,215,500	$92.94	$113M	+76,500	+$45M
Horizon Therapeutics Pub	2.31%, was 2.00%	Add +22.5%	1,012,000	$107.76	$109M	+186,000	+$19M
NBIX, Neurocrine Biosciences	2.28%, was 1.80%	Add +48.4%	1,260,000	$85.17	$107M	+411,100	+$26M
Blueprint Medicines	2.26%, was 1.90%	Add +19.6%	995,000	$107.11	$107M	+163,000	+$21M
Seagen	2.25%, was 2.02%	Add +27.6%	685,000	$154.60	$106M	+148,000	+$15M
SNDX, Syndax Pharmaceuticals	2.24%	Hold	4,823,400	$21.89	$106M	—	—
LLY, Eli Lilly	2.02%, was 1.69%	Add +4.5%	344,800	$276.22	$95M	+14,800	+$19M
Catalent	1.89%, was 1.17%	Add +74.6%	695,000	$128.03	$89M	+297,000	+$36M
NTRA, Natera	1.86%, was 1.58%	Add +47.2%	940,000	$93.39	$88M	+301,300	+$17M
HOLX, Hologic	1.73%, was 1.55%	Add +12.5%	1,064,000	$76.56	$81M	+118,600	+$12M
IOVA, Iovance Biotherapeutics	1.53%, was 0.80%	Add +158.5%	3,780,000	$19.09	$72M	+2,317,800	+$36M
SHC, Sotera Health	1.48%, was 1.38%	Add +24.5%	2,960,000	$23.55	$70M	+582,000	+$7.5M
NUVB, Nuvation Bio	1.33%	Add +1.6%	7,382,488	$8.50	$63M	+119,000	−$9.4M
ALNY, Alnylam Pharmaceuticals	1.33%, was 1.79%	Reduce −13.3%	370,000	$169.58	$63M	−57,000	−$18M
UNH, UnitedHealth Group	1.31%	New	123,100	$502.14	$62M	+123,100	+$62M
VRTX, Vertex Pharmaceuticals	1.30%, was 3.72%	Reduce −69.8%	280,000	$219.60	$61M	−646,400	−$107M
IDYA, Ideaya Biosciences	1.28%	Add +4.8%	2,553,000	$23.64	$60M	+116,000	−$1.8M
RARE	1.25%, was 0.91%	Add +53.8%	700,000	$84.09	$59M	+245,000	+$18M
ARWR, Arrowhead Pharmaceuticals	1.23%, was 0.93%	Add +29.9%	875,000	$66.30	$58M	+201,300	+$16M
Stevanato Group	1.21%	Hold	2,541,893	$22.45	$57M	—	—
Gritstone Bio	1.19%	Reduce −2.0%	4,370,000	$12.86	$56M	−87,831	+$8.1M
Kezar Life Sciences	1.14%, was 0.05%	Add +1141.6%	3,228,200	$16.72	$54M	+2,968,200	+$52M
Adicet Bio	1.13%, was 0.42%	Add +25.4%	3,034,004	$17.49	$53M	+614,404	+$34M
RNA, Avidity Biosciences	0.92%, was 0.90%	Add +10.3%	1,815,000	$23.77	$43M	+170,000	+$2.6M
KYMR, Kymera Therapeutics	0.90%, was 0.67%	Add +30.2%	670,000	$63.49	$43M	+155,500	+$12M
Immunocore	0.89%	Add +12.3%	1,230,000	$34.24	$42M	+134,400	+$1.5M
CRBU, Caribou Biosciences	0.86%	Add +8.1%	2,674,067	$15.09	$40M	+200,000	−$19M
INSM, Insmed	0.84%, was 0.79%	Add +12.2%	1,450,000	$27.24	$39M	+158,000	+$3.9M
Holding	0.81%, was 0.98%	Reduce −25.4%	1,790,000	$21.39	$38M	−608,000	−$6M
PHAT, Phathom Pharmaceuticals	0.79%	New	1,896,000	$19.67	$37M	+1,896,000	+$37M
Holding	0.74%, was 0.43%	Add +0.4%	2,460,000	$14.20	$35M	+10,000	+$15M
AMN, Amn Healthcare Services	0.73%	New	280,100	$122.33	$34M	+280,100	+$34M
Legend Biotech	0.70%, was 1.00%	Reduce −20.4%	711,900	$46.61	$33M	−182,100	−$12M
ATEC, Alphatec	0.67%, was 0.75%	Reduce −0.5%	2,773,000	$11.43	$32M	−13,000	−$2.3M
Bellus Health	0.64%, was 0.67%	Reduce −23.6%	3,775,000	$8.05	$30M	−1,167,000	+$45K
VIR, Vir Biotechnology	0.62%, was 0.50%	Add +35.9%	700,000	$41.87	$29M	+185,000	+$6.9M
AXSM, Axsome Therapeutics	0.62%	New	775,000	$37.78	$29M	+775,000	+$29M
Seaspine	0.58%	Add +3.4%	2,010,000	$13.62	$27M	+67,000	−$3.2M
ALT, Altimmune	0.54%	Add +27.5%	2,765,000	$9.16	$25M	+597,100	+$808K
Viridian Therapeutics	0.54%	New	1,278,261	$19.77	$25M	+1,278,261	+$25M
Holding	0.54%	New	862,000	$29.27	$25M	+862,000	+$25M
Chemocentryx	0.50%	New	644,400	$36.41	$23M	+644,400	+$23M
SIBN, Si-Bone	0.47%, was 0.39%	Add +18.8%	987,400	$22.21	$22M	+156,200	+$4.1M
Cyteir Therapeutics	0.45%	Add +9.9%	1,849,538	$11.37	$21M	+166,097	−$8.5M
Alpine Immune Sciences	0.40%, was 0.46%	Reduce −30.4%	1,345,000	$13.85	$19M	−587,000	−$2M
RLMD, Relmada Therapeutics	0.35%	New	731,536	$22.53	$16M	+731,536	+$16M
SCYX, Scynexis	0.29%, was 0.24%	Add +8.7%	2,239,278	$6.10	$14M	+179,278	+$2.7M
IPSC, Century Therapeutics	0.29%	Add +15.2%	851,522	$15.86	$14M	+112,253	−$5.1M
Phasebio Pharmaceuticals	0.24%	Hold	4,405,000	$2.61	$11M	—	—
Hyperfine	0.23%	New	1,514,410	$7.25	$11M	+1,514,410	+$11M
S, Sentinelone	0.22%	Add +4.0%	208,000	$50.49	$11M	+8,000	−$212K
Graphite Bio	0.19%, was 0.27%	Reduce −5.2%	710,000	$12.43	$8.8M	−38,995	−$3.5M
TCOM, Field Trip Health	0.17%, was 0.36%	Reduce −10.5%	3,205,000	$2.46	$7.9M	−376,000	−$8.6M
TNGX, Tango Therapeutics	0.16%, was 0.09%	Add +135.0%	705,000	$10.94	$7.7M	+405,000	+$3.8M
ACAD, Acadia Pharmaceuticals	0.15%, was 0.20%	Reduce −45.5%	300,000	$23.34	$7M	−250,000	−$2.1M
Instil Bio	0.15%	Hold	408,140	$17.11	$7M	—	—
Talaris Therapeutics	0.15%, was 0.14%	Add 0.0%	455,037	$15.29	$7M	+37	+$788K
DH, Definitive Healthcare	0.14%	New	250,000	$27.33	$6.8M	+250,000	+$6.8M
Eqrx	0.14%	New	1,000,000	$6.82	$6.8M	+1,000,000	+$6.8M
Caremax	0.13%	Hold	827,402	$7.68	$6.4M	—	—
CMPX, Compass Therapeutics	0.13%	New	2,000,000	$3.17	$6.3M	+2,000,000	+$6.3M
GLUE, Monte Rosa Therapeutics	0.13%	Hold	300,000	$20.42	$6.1M	—	—
Werewolf Therapeutics	0.12%, was 0.24%	Reduce −22.4%	485,000	$11.91	$5.8M	−140,120	−$5M
Holding	0.11%	Hold	520,000	$9.69	$5M	—	—
Arya Sciences Acqu Corporation IV	0.11%	Hold	500,000	$9.92	$5M	—	—
Holding	0.10%	Hold	500,000	$9.86	$4.9M	—	—
Science 37	0.10%	New	394,000	$12.47	$4.9M	+394,000	+$4.9M
Bcls Acquisition	0.10%	Hold	500,000	$9.80	$4.9M	—	—
Panacea Acquisition Corporation II	0.10%	Hold	500,000	$9.70	$4.9M	—	—
TRDA, Entrada Therapeutics	0.09%	New	255,000	$17.12	$4.4M	+255,000	+$4.4M
Sema4	0.09%, was 0.28%	Reduce −42.8%	950,000	$4.46	$4.2M	−710,000	−$8.4M
Health Sciences Acq Corporation 2	0.09%	Hold	400,000	$10.08	$4M	—	—
Helix Acquisition	0.08%	Hold	400,000	$9.89	$4M	—	—
Somalogic	0.08%	Hold	330,000	$11.64	$3.8M	—	—
Merus	0.07%	New	103,000	$31.80	$3.3M	+103,000	+$3.3M
Oncosec Medical	0.06%	Hold	2,945,000	$0.9596	$2.8M	—	—
Holding	0.04%	Hold	200,000	$9.93	$2M	—	—
Holding	0.04%	Hold	200,000	$9.90	$2M	—	—
Holding	0.04%	Hold	200,000	$9.89	$2M	—	—
Social Cap Suvretta Hlds CP	0.04%	Hold	200,000	$9.82	$2M	—	—
Shattuck Labs	0.03%, was 0.91%	Reduce −91.9%	165,000	$8.51	$1.4M	−1,860,000	−$40M
Ziopharm Oncology	0.01%, was 0.12%	Reduce −80.3%	590,000	$1.09	$643K	−2,410,000	−$4.8M

Showing top 50 of 94 by value

Exits / last held

Gone since 2021 Q3, shown at their last reported size.

Stock	% of portfolio	Recent activity	Reported price*	Value	Share change	$ change
REGN, Regeneron	2.04%	Exit	$605.18	$92M	−152,300	−$92M
Exact Sciences	0.78%	Exit	$95.45	$35M	−369,000	−$35M
CMPS, Compass Pathways	0.77%	Exit	$29.87	$35M	−1,162,000	−$35M
INTC, Intellia Therapeutics	0.75%	Exit	$134.15	$34M	−251,000	−$34M
I Mab	0.73%	Exit	$72.49	$33M	−454,000	−$33M
Sana Biotechnology	0.39%	Exit	$22.52	$17M	−774,644	−$17M
PATH, Uipath	0.37%	Exit	$52.61	$17M	−319,000	−$17M
LFST, Lifestance Health Group	0.32%	Exit	$14.50	$15M	−1,000,000	−$15M
GH Research	0.27%	Exit	$22.06	$12M	−560,000	−$12M
Ac Immune	0.26%	Exit	$6.71	$12M	−1,739,600	−$12M
Harpoon Therapeutics	0.21%	Exit	$7.90	$9.4M	−1,190,600	−$9.4M
Engagesmart	0.21%	Exit	$34.06	$9.4M	−275,000	−$9.4M
Orchard Therapeutics	0.20%	Exit	$2.30	$8.8M	−3,836,798	−$8.8M
Zeta Global	0.17%	Exit	$5.86	$7.6M	−1,300,000	−$7.6M
Holding	0.13%	Exit	$172.11	$6M	−35,000	−$6M
Keros Therapeutics	0.13%	Exit	$39.56	$5.7M	−145,100	−$5.7M
Healthcor Catalio Acqu	0.11%	Exit	$9.90	$5M	−500,000	−$5M
Lifesci Acquisition II	0.09%	Exit	$9.80	$3.9M	−400,000	−$3.9M
ZLAB, Zai Lab	0.08%	Exit	$105.39	$3.8M	−35,600	−$3.8M
Nautilus Biotechnology	0.08%	Exit	$6.14	$3.7M	−600,000	−$3.7M
Sight Sciences	0.07%	Exit	$22.70	$3.3M	−145,189	−$3.3M
Atai Life Sciences	0.07%	Exit	$14.79	$3.2M	−218,730	−$3.2M

Filings history

20 periods, with AUM normalized

Newest 13Fs

Period	Holds	AUM	QoQ	Form	Filed	Filing ID
2026 Q2	45	$624M	+41.2%	13F-HR	8/14/2026	000179182726000005
2026 Q1	45	$494M	—	new holds	5/28/2026	000179182726000004
2026 Q1	46	$442M	+27.4%	13F-HR	5/13/2026	000179182726000003
2025 Q4	39	$347M	−21.0%	13F-HR	2/13/2026	000179182726000002
2025 Q3	43	$439M	−12.5%	13F-HR	11/14/2025	000179182725000008
2025 Q2	56	$502M	−4.4%	13F-HR	8/14/2025	000179182725000007
2025 Q1	67	$525M	−48.4%	13F-HR	5/15/2025	000179182725000005
2024 Q4	63	$1B	−48.1%	13F-HR	2/14/2025	000179182725000002
2024 Q3	81	$2B	−16.7%	13F-HR	11/14/2024	000179182724000011
2024 Q2	85	$2.4B	−24.1%	13F-HR	8/14/2024	000179182724000007
2024 Q1	90	$3.1B	+13.0%	13F-HR	5/15/2024	000179182724000004
2023 Q4	74	$2.7B	+10.5%	13F-HR	2/14/2024	000179182724000002
2023 Q3	83	$2.5B	−13.3%	13F-HR	11/14/2023	000179182723000006
2023 Q2	93	$2.9B	−5.0%	13F-HR	8/14/2023	000179182723000004
2023 Q1	83	$3B	−34.7%	13F-HR	5/15/2023	000179182723000003
2022 Q4	85	$4.6B	−6.2%	13F-HR	2/14/2023	000179182723000002
2022 Q3	97	$4.9B	+12.9%	13F-HR	11/14/2022	000179182722000008
2022 Q2	82	$4.4B	−9.3%	13F-HR	8/15/2022	000179182722000006
2022 Q1	92	$4.8B	+1.9%	13F-HR	5/16/2022	000179182722000004
2021 Q4	97	$4.7B	+4.5%	13F-HR	2/14/2022	000179182722000002
2021 Q3	105	$4.5B	—	13F-HR	11/15/2021	000179182721000006

About

Avidity Partners Management LP

21 processed 13Fs on this site, 2021 Q3 to 2026 Q2

Entity: Avidity Partners Management LP
Notable person: David Witzke
Location: Dallas, TX
All SEC filings: View on sec.gov

Filings history

Avidity Partners Management LP

Further reading