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

2022 Q1 2021 Q4, filed 16 May, long equity only

Download CSV Download Excel All activity


AZNN	5.11%, was 3.54%	Add +29.0%	3,700,000	$66.34	$245M	+832,800	+$78M
ABBV, AbbVie	4.95%, was 5.70%	Reduce −26.1%	1,466,100	$162.11	$238M	−518,900	−$31M
ARVN, Arvinas	4.09%	Add +15.3%	2,915,300	$67.30	$196M	+387,327	−$11M
ELV, Anthem	4.09%, was 3.16%	Add +24.4%	399,400	$491.22	$196M	+78,400	+$47M
MRK, Merck	4.05%	New	2,370,000	$82.05	$194M	+2,370,000	+$194M
AVTR, Avantor	3.99%	Add +18.3%	5,668,300	$33.82	$192M	+876,300	−$10M
BAX, Baxter International	3.09%	Add +8.5%	1,915,500	$77.54	$149M	+150,500	−$3M
ZNTL, Zentalis Pharmaceuticals	3.05%	Add +17.0%	3,176,999	$46.14	$147M	+461,999	−$82M
BHVN, Biohaven	3.04%	Add +8.0%	1,231,000	$118.57	$146M	+91,000	−$11M
VRTX, Vertex Pharmaceuticals	2.96%, was 1.30%	Add +94.9%	545,600	$260.97	$142M	+265,600	+$81M
UNH, UnitedHealth Group	2.76%, was 1.31%	Add +110.9%	259,600	$509.97	$132M	+136,500	+$71M
UTHR, United Therapeutics	2.69%, was 2.45%	Add +34.4%	718,946	$179.41	$129M	+183,946	+$13M
Horizon Therapeutics Pub	2.48%, was 2.31%	Add +11.8%	1,131,400	$105.21	$119M	+119,400	+$10M
Mirati Therapeutics	2.38%	Add +72.7%	1,393,000	$82.22	$115M	+586,600	−$3.8M
Iveric Bio	2.27%, was 2.47%	Reduce −6.9%	6,475,400	$16.83	$109M	−479,600	−$7.3M
NBIX, Neurocrine Biosciences	2.26%, was 2.28%	Reduce −7.9%	1,160,000	$93.75	$109M	−100,000	+$1.4M
IOVA, Iovance Biotherapeutics	2.10%, was 1.53%	Add +59.9%	6,043,219	$16.65	$101M	+2,263,219	+$28M
ISRG, Intuitive Surgical	2.04%	New	325,000	$301.68	$98M	+325,000	+$98M
Catalent	1.81%	Add +12.5%	782,000	$110.90	$87M	+87,000	−$2.3M
HUM, Humana	1.80%	New	198,900	$435.17	$87M	+198,900	+$87M
SNDX, Syndax Pharmaceuticals	1.75%	Hold	4,823,400	$17.38	$84M	—	—
BIIB, Biogen	1.60%	New	365,000	$210.60	$77M	+365,000	+$77M
RARE	1.31%, was 1.25%	Add +24.1%	869,000	$72.62	$63M	+169,000	+$4.2M
JNJ, Johnson & Johnson	1.31%	New	354,000	$177.23	$63M	+354,000	+$63M
Adicet Bio	1.30%, was 1.13%	Add +2.8%	3,120,000	$19.97	$62M	+85,996	+$9.2M
Kezar Life Sciences	1.22%, was 1.14%	Add +9.0%	3,518,000	$16.62	$58M	+289,800	+$4.5M
MCK, McKesson	1.21%	New	189,500	$306.13	$58M	+189,500	+$58M
ARGX, Argenx	1.16%	New	176,000	$315.31	$55M	+176,000	+$55M
BSX, Boston Scientific	1.10%	New	1,196,100	$44.29	$53M	+1,196,100	+$53M
NTRA, Natera	1.10%	Add +38.3%	1,300,000	$40.68	$53M	+360,000	−$35M
EW, Edwards Lifesciences	1.08%	New	440,000	$117.72	$52M	+440,000	+$52M
ARWR, Arrowhead Pharmaceuticals	0.91%	Add +9.1%	955,000	$45.99	$44M	+80,000	−$14M
Immunocore	0.85%	Add +10.9%	1,363,800	$29.90	$41M	+133,800	−$1.3M
Legend Biotech	0.83%, was 0.70%	Add +53.8%	1,095,000	$36.34	$40M	+383,100	+$6.6M
XBI, SPDR Ser Trust	0.82%	New	440,000	$89.88	$40M	+440,000	+$40M
BHC, Bausch Health Companies	0.81%	New	1,694,700	$22.85	$39M	+1,694,700	+$39M
RNA, Avidity Biosciences	0.79%	Add +12.7%	2,045,000	$18.47	$38M	+230,000	−$5.4M
INSM, Insmed	0.66%, was 0.84%	Reduce −6.6%	1,354,539	$23.50	$32M	−95,461	−$7.7M
ATEC, Alphatec	0.66%, was 0.67%	Reduce −1.3%	2,735,600	$11.50	$31M	−37,400	−$236K
IDYA, Ideaya Biosciences	0.63%	Add +5.4%	2,690,000	$11.19	$30M	+137,000	−$30M
Chemocentryx	0.61%, was 0.50%	Add +82.3%	1,175,000	$25.07	$29M	+530,600	+$6M
AXSM, Axsome Therapeutics	0.61%, was 0.62%	Reduce −8.3%	711,000	$41.39	$29M	−64,000	+$148K
RCUS, Arcus Biosciences	0.60%	New	912,000	$31.56	$29M	+912,000	+$29M
INTC, Intellia Therapeutics	0.59%	New	390,075	$72.67	$28M	+390,075	+$28M
PHAT, Phathom Pharmaceuticals	0.55%	Add +2.6%	1,946,000	$13.61	$26M	+50,000	−$11M
CRBU, Caribou Biosciences	0.54%	Add +5.4%	2,819,067	$9.18	$26M	+145,000	−$14M
NUVB, Nuvation Bio	0.53%, was 1.33%	Reduce −34.2%	4,855,006	$5.26	$26M	−2,527,482	−$37M
Bellus Health	0.53%, was 0.64%	Reduce −2.4%	3,685,000	$6.88	$25M	−90,000	−$5M
Seaspine	0.51%	Hold	2,010,000	$12.16	$24M	—	—
PEN, Penumbra	0.48%	New	104,000	$222.13	$23M	+104,000	+$23M
SIBN, Si-Bone	0.47%	Add +1.3%	1,000,000	$22.60	$23M	+12,600	+$670K
VIR, Vir Biotechnology	0.42%	Add +11.4%	780,000	$25.72	$20M	+80,000	−$9.2M
Viridian Therapeutics	0.40%, was 0.54%	Reduce −18.6%	1,040,000	$18.49	$19M	−238,261	−$6M
Blueprint Medicines	0.39%, was 2.26%	Reduce −70.7%	291,184	$63.88	$19M	−703,816	−$88M
ALT, Altimmune	0.36%	Add +3.6%	2,865,000	$6.09	$17M	+100,000	−$7.9M
Holding	0.32%	Hold	2,460,000	$6.18	$15M	—	—
Seagen	0.30%, was 2.25%	Reduce −85.4%	100,000	$144.05	$14M	−585,000	−$91M
LKFT, Galapagos	0.28%	New	215,000	$62.02	$13M	+215,000	+$13M
IPSC, Century Therapeutics	0.23%	Add +1.6%	865,000	$12.59	$11M	+13,478	−$2.6M
Alpine Immune Sciences	0.23%, was 0.40%	Reduce −10.3%	1,207,000	$8.97	$11M	−138,000	−$7.8M
APLS, Apellis Pharmaceuticals	0.22%	New	210,000	$50.81	$11M	+210,000	+$11M
ANTX, An2 Therapeutics	0.22%	New	688,330	$15.07	$10M	+688,330	+$10M
ERAS, Erasca	0.18%	New	995,000	$8.60	$8.6M	+995,000	+$8.6M
S, Sentinelone	0.16%, was 0.22%	Reduce −1.7%	204,500	$38.74	$7.9M	−3,500	−$2.6M
Cyteir Therapeutics	0.15%	Add 0.0%	1,850,000	$3.77	$7M	+462	−$14M
Phasebio Pharmaceuticals	0.12%	Hold	4,405,000	$1.32	$5.8M	—	—
Caremax	0.12%, was 0.13%	Reduce −8.7%	755,329	$7.47	$5.6M	−72,073	−$712K
TNGX, Tango Therapeutics	0.11%	Add +2.3%	721,000	$7.58	$5.5M	+16,000	−$2.2M
Hyperfine	0.11%, was 0.23%	Reduce −0.7%	1,503,754	$3.54	$5.3M	−10,656	−$5.7M
Holding	0.11%	Hold	520,000	$9.78	$5.1M	—	—
Bcls Acquisition	0.10%	Hold	500,000	$9.87	$4.9M	—	—
Holding	0.10%	Hold	500,000	$9.87	$4.9M	—	—
Arya Sciences Acqu Corporation IV	0.10%	Hold	500,000	$9.80	$4.9M	—	—
Panacea Acquisition Corporation II	0.10%	Hold	500,000	$9.75	$4.9M	—	—
Helix Acquisition	0.09%	Hold	400,000	$11.10	$4.4M	—	—
TCOM, Field Trip Health	0.08%, was 0.17%	Reduce −7.1%	2,976,000	$1.34	$4M	−229,000	−$3.9M
Health Sciences Acq Corporation 2	0.08%	Hold	400,000	$9.91	$4M	—	—
Graphite Bio	0.08%	Hold	710,000	$5.10	$3.6M	—	—
Oncosec Medical	0.07%	Hold	2,945,000	$1.15	$3.4M	—	—
Otonomy	0.07%	New	1,349,905	$2.40	$3.2M	+1,349,905	+$3.2M
Sema4	0.06%	Hold	950,000	$3.07	$2.9M	—	—
CMPX, Compass Therapeutics	0.06%	Hold	2,000,000	$1.37	$2.7M	—	—
Gritstone Bio	0.05%, was 1.19%	Reduce −87.2%	560,000	$4.12	$2.3M	−3,810,000	−$54M
Science 37	0.05%	Add +9.1%	430,000	$5.35	$2.3M	+36,000	−$2.6M
SCYX, Scynexis	0.04%, was 0.29%	Reduce −75.7%	544,043	$3.91	$2.1M	−1,695,235	−$12M
Holding	0.04%	Hold	200,000	$9.90	$2M	—	—
Holding	0.04%	Hold	200,000	$9.89	$2M	—	—
Holding	0.04%	Hold	200,000	$9.75	$2M	—	—
Social Cap Suvretta Hlds CP	0.04%	Hold	200,000	$9.74	$1.9M	—	—

Showing top 50 of 89 by value

Exits / last held

Gone since 2021 Q4, shown at their last reported size.

Stock	% of portfolio	Recent activity	Reported price*	Value	Share change	$ change
PFE, Pfizer	2.62%	Exit	$59.05	$123M	−2,090,000	−$123M
Arena Pharmaceuticals	2.40%	Exit	$92.94	$113M	−1,215,500	−$113M
LLY, Eli Lilly	2.02%	Exit	$276.22	$95M	−344,800	−$95M
HOLX, Hologic	1.73%	Exit	$76.56	$81M	−1,064,000	−$81M
SHC, Sotera Health	1.48%	Exit	$23.55	$70M	−2,960,000	−$70M
ALNY, Alnylam Pharmaceuticals	1.33%	Exit	$169.58	$63M	−370,000	−$63M
Stevanato Group	1.21%	Exit	$22.45	$57M	−2,541,893	−$57M
KYMR, Kymera Therapeutics	0.90%	Exit	$63.49	$43M	−670,000	−$43M
Holding	0.81%	Exit	$21.39	$38M	−1,790,000	−$38M
AMN, Amn Healthcare Services	0.73%	Exit	$122.33	$34M	−280,100	−$34M
Holding	0.54%	Exit	$29.27	$25M	−862,000	−$25M
RLMD, Relmada Therapeutics	0.35%	Exit	$22.53	$16M	−731,536	−$16M
ACAD, Acadia Pharmaceuticals	0.15%	Exit	$23.34	$7M	−300,000	−$7M
Instil Bio	0.15%	Exit	$17.11	$7M	−408,140	−$7M
Talaris Therapeutics	0.15%	Exit	$15.29	$7M	−455,037	−$7M
DH, Definitive Healthcare	0.14%	Exit	$27.33	$6.8M	−250,000	−$6.8M
Eqrx	0.14%	Exit	$6.82	$6.8M	−1,000,000	−$6.8M
GLUE, Monte Rosa Therapeutics	0.13%	Exit	$20.42	$6.1M	−300,000	−$6.1M
Werewolf Therapeutics	0.12%	Exit	$11.91	$5.8M	−485,000	−$5.8M
TRDA, Entrada Therapeutics	0.09%	Exit	$17.12	$4.4M	−255,000	−$4.4M
Somalogic	0.08%	Exit	$11.64	$3.8M	−330,000	−$3.8M
Merus	0.07%	Exit	$31.80	$3.3M	−103,000	−$3.3M
Shattuck Labs	0.03%	Exit	$8.51	$1.4M	−165,000	−$1.4M
Ziopharm Oncology	0.01%	Exit	$1.09	$643K	−590,000	−$643K

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