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

2023 Q1 2022 Q4, filed 15 May, long equity only

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ARVN, Arvinas	3.88%	Reduce −13.7%	4,273,900	$27.32	$117M	−676,100	−$53M
SGRY, Surgery Partners	3.84%, was 1.88%	Add +7.8%	3,355,900	$34.47	$116M	+243,900	+$29M
BIO, Bio Rad Labs	3.52%, was 0.84%	Add +140.2%	221,500	$479.02	$106M	+129,300	+$67M
ARGX, Argenx	3.47%, was 5.13%	Reduce −55.1%	280,700	$372.58	$105M	−344,300	−$132M
JAZZ, Jazz Pharmaceuticals	3.29%	Reduce −6.8%	677,900	$146.33	$99M	−49,641	−$17M
REGN, Regeneron	3.25%	New	119,100	$821.67	$98M	+119,100	+$98M
Akero Therapeutics	3.11%, was 4.54%	Reduce −36.0%	2,447,000	$38.26	$94M	−1,378,000	−$116M
THC, Tenet Healthcare	2.90%, was 0.76%	Add +105.2%	1,472,000	$59.42	$87M	+754,700	+$52M
RARE	2.83%, was 3.00%	Reduce −28.9%	2,126,900	$40.10	$85M	−863,100	−$53M
UHS, Universal Health Services	2.83%	Reduce −18.8%	670,000	$127.10	$85M	−155,600	−$31M
ACHC	2.79%, was 2.08%	Add 0.0%	1,165,300	$72.25	$84M	+300	−$12M
NBIX, Neurocrine Biosciences	2.74%, was 4.61%	Reduce −54.2%	815,700	$101.22	$83M	−964,300	−$130M
SNDX, Syndax Pharmaceuticals	2.71%, was 3.23%	Reduce −34.1%	3,865,300	$21.12	$82M	−1,995,700	−$68M
Karuna Therapeutics	2.43%, was 1.27%	Add +35.1%	403,800	$181.64	$73M	+104,800	+$15M
BDX, Becton Dickinson	2.37%	New	288,000	$247.54	$71M	+288,000	+$71M
PLRX, Pliant Therapeutics	2.35%, was 0.94%	Add +19.0%	2,665,000	$26.60	$71M	+424,600	+$28M
ZTS, Zoetis	2.25%	New	407,500	$166.44	$68M	+407,500	+$68M
Ventyx Biosciences	2.13%, was 0.91%	Add +49.2%	1,917,800	$33.50	$64M	+632,800	+$22M
MRK, Merck	2.12%	New	600,000	$106.39	$64M	+600,000	+$64M
Sarepta Therapeutics	1.90%, was 2.96%	Reduce −60.6%	416,000	$137.83	$57M	−639,000	−$79M
Legend Biotech	1.79%, was 1.05%	Add +15.5%	1,120,500	$48.22	$54M	+150,500	+$5.6M
PRTA, Prothena	1.72%, was 3.85%	Reduce −63.8%	1,068,200	$48.47	$52M	−1,884,800	−$126M
IDYA, Ideaya Biosciences	1.67%	Reduce −4.0%	3,673,400	$13.73	$50M	−151,400	−$19M
ZNTL, Zentalis Pharmaceuticals	1.67%, was 2.25%	Reduce −43.1%	2,929,300	$17.20	$50M	−2,220,700	−$53M
Iveric Bio	1.51%, was 0.39%	Add +122.9%	1,869,200	$24.33	$45M	+1,030,793	+$28M
ARWR, Arrowhead Pharmaceuticals	1.47%, was 1.21%	Add +26.6%	1,741,300	$25.40	$44M	+366,300	−$12M
PACB	1.47%	New	3,812,600	$11.58	$44M	+3,812,600	+$44M
BSX, Boston Scientific	1.41%, was 3.26%	Reduce −73.9%	850,000	$50.03	$43M	−2,406,700	−$108M
AXSM, Axsome Therapeutics	1.27%	Reduce −7.6%	619,200	$61.68	$38M	−50,800	−$13M
VIR, Vir Biotechnology	1.27%, was 0.47%	Add +93.0%	1,640,200	$23.27	$38M	+790,200	+$17M
Immunocore	1.26%, was 1.43%	Reduce −33.3%	769,800	$49.44	$38M	−384,200	−$28M
Karyopharm Therapeutics	1.24%	Hold	9,633,911	$3.89	$37M	—	—
ABT, Abbott Laboratories	1.19%	New	354,000	$101.26	$36M	+354,000	+$36M
BIIB, Biogen	1.19%	New	128,800	$278.03	$36M	+128,800	+$36M
Bellus Health	1.09%	Reduce −1.0%	4,553,577	$7.20	$33M	−46,421	−$5M
ICLR, Icon	1.01%	Reduce −33.5%	142,900	$213.59	$31M	−72,100	−$11M
BMRN, Biomarin Pharmaceutical	0.97%	New	300,575	$97.24	$29M	+300,575	+$29M
RVMD, Revolution Medicines	0.97%, was 1.28%	Reduce −45.7%	1,344,800	$21.66	$29M	−1,130,200	−$30M
89bio	0.93%	New	1,842,976	$15.23	$28M	+1,842,976	+$28M
AMLX, Amylyx Pharmaceuticals	0.88%	New	900,000	$29.34	$26M	+900,000	+$26M
Curevac	0.82%	New	3,550,000	$6.97	$25M	+3,550,000	+$25M
AVTR, Avantor	0.79%	New	1,125,000	$21.14	$24M	+1,125,000	+$24M
Nanostring Technologies	0.73%, was 0.36%	Add +7.8%	2,217,000	$9.90	$22M	+159,800	+$5.6M
Fusion Pharmaceuticals	0.71%	New	5,700,000	$3.77	$21M	+5,700,000	+$21M
RCKT, Rocket Pharmaceuticals	0.71%	Reduce −18.5%	1,244,400	$17.13	$21M	−282,687	−$8.6M
Kezar Life Sciences	0.68%, was 1.03%	Reduce −3.9%	6,519,400	$3.13	$20M	−263,000	−$27M
BHVN, Biohaven	0.67%	Reduce −0.3%	1,487,200	$13.66	$20M	−4,800	−$394K
COR, Amerisourcebergen	0.67%	New	126,600	$160.11	$20M	+126,600	+$20M
MLYS, Mineralys Therapeutics	0.66%	New	1,263,800	$15.66	$20M	+1,263,800	+$20M
Verve Therapeutics	0.65%, was 0.66%	Reduce −13.6%	1,351,700	$14.42	$19M	−213,300	−$11M
RNA, Avidity Biosciences	0.64%, was 1.57%	Reduce −61.4%	1,265,545	$15.35	$19M	−2,009,455	−$53M
PCVX, Vaxcyte	0.63%, was 1.68%	Reduce −68.4%	510,000	$37.48	$19M	−1,105,400	−$58M
ARQT, Arcutis Biotherapeutics	0.59%	Reduce −7.2%	1,628,500	$11.00	$18M	−126,500	−$8.1M
Holding	0.59%	New	878,800	$20.08	$18M	+878,800	+$18M
Point Biopharma Global	0.58%	Reduce −0.9%	2,411,600	$7.27	$18M	−20,800	−$200K
DXCM, DexCom	0.57%, was 1.86%	Reduce −80.4%	148,000	$116.18	$17M	−608,800	−$69M
BBIO, Bridgebio	0.55%	New	1,000,000	$16.58	$17M	+1,000,000	+$17M
IMVT, Immunovant	0.54%	New	1,043,000	$15.51	$16M	+1,043,000	+$16M
INTC, Intellia Therapeutics	0.52%	Reduce −34.7%	417,000	$37.27	$16M	−221,200	−$6.7M
CRBU, Caribou Biosciences	0.49%	Reduce −4.3%	2,758,600	$5.31	$15M	−124,000	−$3.5M
PHAT, Phathom Pharmaceuticals	0.49%, was 0.46%	Add +7.8%	2,048,600	$7.14	$15M	+148,600	−$6.7M
Mersana Therapeutics	0.47%	New	3,433,233	$4.11	$14M	+3,433,233	+$14M
NTRA, Natera	0.46%, was 1.57%	Reduce −86.1%	249,900	$55.52	$14M	−1,549,000	−$58M
TWST, Twist Bioscience	0.41%, was 0.32%	Add +34.0%	819,000	$15.08	$12M	+208,000	−$2.2M
COLL, Collegium Pharmaceutical	0.31%, was 0.02%	Add +917.2%	385,500	$23.99	$9.2M	+347,602	+$8.4M
CYTK, Cytokinetics	0.29%, was 0.42%	Reduce −40.1%	252,000	$35.19	$8.9M	−168,700	−$10M
Alpine Immune Sciences	0.25%	Reduce −3.8%	989,500	$7.72	$7.6M	−38,700	+$82K
Kinnate Biopharma	0.24%	Reduce −4.3%	1,160,000	$6.25	$7.3M	−52,700	−$147K
ANTX, An2 Therapeutics	0.24%	Reduce −2.7%	723,200	$9.87	$7.1M	−20,400	+$51K
CMPX, Compass Therapeutics	0.20%, was 0.22%	Reduce −8.8%	1,825,000	$3.27	$6M	−175,000	−$4.1M
ALT, Altimmune	0.18%, was 1.42%	Reduce −67.0%	1,315,200	$4.22	$5.6M	−2,674,800	−$60M
GERN, Geron	0.15%	New	2,128,000	$2.17	$4.6M	+2,128,000	+$4.6M
IPSC, Century Therapeutics	0.15%	Reduce −2.7%	1,268,100	$3.47	$4.4M	−35,500	−$2.3M
Sangamo Therapeutics	0.14%, was 0.19%	Reduce −10.1%	2,470,000	$1.76	$4.3M	−278,300	−$4.3M
Holding	0.11%	New	4,281,700	$0.8090	$3.5M	+4,281,700	+$3.5M
Cyteir Therapeutics	0.11%	Reduce −1.8%	1,764,100	$1.82	$3.2M	−31,700	+$248K
Syros Pharmaceuticals	0.08%, was 0.07%	Add +0.5%	904,630	$2.67	$2.4M	+4,630	−$816K
Hyperfine	0.07%	Hold	1,503,754	$1.44	$2.2M	—	—
Caremax	0.07%	Hold	755,329	$2.67	$2M	—	—
BCAB, Bioatla	0.05%, was 0.23%	Reduce −52.2%	602,500	$2.68	$1.6M	−657,500	−$8.8M
Ac Immune	0.03%	Hold	325,400	$2.34	$761K	—	—
Reunion Neuroscience	0.00%, was 0.01%	Reduce −73.0%	151,098	$0.6904	$104K	−409,202	−$400K

Showing top 50 of 82 by value

Exits / last held

Gone since 2022 Q4, shown at their last reported size.

Stock	% of portfolio	Recent activity	Reported price*	Value	Share change	$ change
UTHR, United Therapeutics	4.73%	Exit	$278.09	$218M	−785,500	−$218M
MDGL, Madrigal Pharmaceuticals	2.70%	Exit	$290.25	$125M	−430,000	−$125M
AZNN	1.76%	Exit	$67.80	$81M	−1,200,000	−$81M
LLY, Eli Lilly	1.72%	Exit	$365.84	$79M	−217,000	−$79M
VRTX, Vertex Pharmaceuticals	1.08%	Exit	$288.78	$50M	−172,000	−$50M
DGX, Quest Diagnostics	0.87%	Exit	$156.44	$40M	−258,000	−$40M
BNTX, Biontech	0.70%	Exit	$150.22	$32M	−215,400	−$32M
Intra-Cellular Therapies	0.58%	Exit	$52.92	$27M	−504,000	−$27M
Prometheus Biosciences	0.49%	Exit	$110.00	$22M	−204,000	−$22M
Holding	0.40%	Exit	$16.39	$18M	−1,126,000	−$18M
Holding	0.11%	Exit	$10.07	$5.2M	−520,000	−$5.2M
Graphite Bio	0.11%	Exit	$3.32	$5.2M	−1,575,000	−$5.2M
Arya Sciences Acqu Corporation IV	0.11%	Exit	$10.10	$5.1M	−500,000	−$5.1M
Panacea Acquisition Corporation II	0.11%	Exit	$10.05	$5M	−500,000	−$5M
Holding	0.10%	Exit	$2.52	$4.7M	−1,855,400	−$4.7M
Health Sciences Acq Corporation 2	0.09%	Exit	$9.98	$4M	−400,000	−$4M
Holding	0.04%	Exit	$10.06	$2M	−200,000	−$2M
Social Cap Suvretta Hlds CP	0.04%	Exit	$10.05	$2M	−200,000	−$2M
SCYX, Scynexis	0.04%	Exit	$1.56	$1.8M	−1,140,600	−$1.8M
FATE, Fate Therapeutics	0.02%	Exit	$10.09	$1.1M	−104,653	−$1.1M
ZLAB, Zai Lab	0.02%	Exit	$30.69	$961K	−31,309	−$961K

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