2026 Q1 Portfolio Activity
In 2026 Q1, EcoR1 Capital, LLC maintained a portfolio of 41 distinct positions. The most significant new addition was AKTIS ONCOLOGY INC, now representing 3.66% of the total fund value. They heavily accumulated shares in CENTESSA PHARMACEUTICALS PLC, increasing the position by 92.6%. The fund also reduced its exposure to CENTESSA PHARMACEUTICALS PLC by 86.8%.
Position History
hover any row below to update
Loading…
Total Positions
41
Quarter
2026 Q1
Top Holding
ZYME (24.4%)
Top 10 Concentration
88.9%
Turnover Rate
23.4%
Sector HHI
0.18
Items per page:
Showing 1-41 of 41
EcoR1 Capital, LLC Full Holdings List — 2026 Q1
| Stock | History | Sector / Type | Port % | Prev % | Rank / Prev | Conviction | Change | % Change | Influence | Shares | Mkt Value | Avg Cost | Price Held | 1st Owned | Source | Source Date | Date Reported | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
ZYME
ZYMEWORKS INC
|
Healthcare | 24.41% | 27.44% |
#1
Prev: #1
|
7.0 |
—
|
no change | no change |
P
S
|
22,970,388 | $575,178,516 | 2022 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ANAB
ANAPTYSBIO INC
|
Healthcare | 18.55% | 17.33% |
#2
Prev: #2
|
6.5 |
—
|
no change | no change |
P
S
|
7,880,094 | $437,030,013 | 2019 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
JAZZ
JAZZ PHARMACEUT...
|
Healthcare | 13.69% | 13.16% |
#3
Prev: #3
|
6.0 |
—
|
no change | no change |
P
S
|
1,706,469 | $322,607,964 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CNTA
CENTESSA PHARMA...
|
Healthcare | 10.11% | 3.53% |
#4
1
Prev: #5
|
7.5 |
—
|
2,885,000 | 92.6% |
P
S
|
6,000,000 | $238,320,000 | 2021 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CRNX
CRINETICS PHARM...
|
Healthcare | 6.61% | 9.06% |
#5
1
Prev: #4
|
4.1 |
—
|
no change | no change |
P
S
|
4,288,120 | $155,744,518 | 2020 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
N/A
AKTIS ONCOLOGY ...
|
|
Unknown | 3.66% | — |
#6
Prev: #—
|
5.0 |
—
|
4,824,469 | — |
NEW
|
4,824,469 | $86,309,750 | — | 13F Filing | 2026-03-31 | 2026-05-15 | ||
|
ORIC
ORIC PHARMACEUT...
|
Healthcare | 3.62% | 2.50% |
#7
2
Prev: #9
|
2.4 |
—
|
no change | no change |
P
S
|
6,728,116 | $85,245,230 | 2020 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CGON
CG ONCOLOGY INC
|
Healthcare | 3.17% | 1.45% |
#8
6
Prev: #14
|
3.8 |
—
|
330,000 | 42.7% |
P
S
|
1,102,000 | $74,583,360 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CRSP
CRISPR THERAPEU...
|
Healthcare | 2.80% | 3.31% |
#9
3
Prev: #6
|
2.1 |
—
|
no change | no change |
P
S
|
1,389,276 | $66,087,859 | 2018 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ETON
ETON PHARMACEUT...
|
Healthcare | 2.27% | 1.56% |
#10
3
Prev: #13
|
2.9 |
—
|
141,394 | 7.0% |
P
S
|
2,171,938 | $53,603,430 | 2024 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
GLPG
GALAPAGOS NV
|
Healthcare | 2.12% | 2.47% |
#11
1
Prev: #10
|
1.8 |
—
|
no change | no change |
P
S
|
1,667,119 | $50,013,570 | 2015 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
XNCR
XENCOR INC
|
Healthcare | 1.12% | 2.26% |
#12
1
Prev: #11
|
0.4 |
—
|
-1,068,112 | -32.9% |
P
S
|
2,183,000 | $26,326,980 | 2016 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
NGNE
NEUROGENE INC
|
Healthcare | 1.09% | 1.19% |
#13
3
Prev: #16
|
1.4 |
—
|
no change | no change |
P
S
|
1,271,342 | $25,630,255 | 2023 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
BBOT
BRIDGEBIO ONCOL...
|
Healthcare | 1.07% | 1.60% |
#14
2
Prev: #12
|
1.4 |
—
|
no change | no change |
P
S
|
2,823,126 | $25,266,978 | 2025 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MBX
MBX BIOSCIENCES...
|
Healthcare | 0.98% | 3.04% |
#15
8
Prev: #7
|
0.4 |
—
|
-1,346,604 | -63.4% |
P
S
|
777,000 | $23,193,450 | 2024 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
RLAY
RELAY THERAPEUT...
|
Healthcare | 0.80% | — |
#16
Prev: #—
|
3.8 |
—
|
1,904,762 | — |
NEW
|
1,904,762 | $18,952,382 | 2020 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CNTA
CALL
CENTESSA PHARMA...
|
CALL Option | 0.69% | — |
#17
Prev: #—
|
3.8 |
—
|
410,800 | — |
NEW
|
410,800 | $16,316,976 | 2021 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ZBIO
ZENAS BIOPHARMA...
|
Healthcare | 0.66% | 1.30% |
#18
3
Prev: #15
|
1.3 |
—
|
no change | no change |
P
S
|
789,500 | $15,434,725 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ERAS
ERASCA INC
|
Healthcare | 0.62% | — |
#19
Prev: #—
|
3.7 |
—
|
900,000 | — |
NEW
|
900,000 | $14,562,000 | 2021 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
N/A
EIKON THERAPEUT...
|
|
Unknown | 0.33% | — |
#20
Prev: #—
|
3.6 |
—
|
732,606 | — |
NEW
|
732,606 | $7,750,971 | — | 13F Filing | 2026-03-31 | 2026-05-15 | ||
|
REPL
REPLIMUNE GROUP...
|
Healthcare | 0.32% | — |
#21
Prev: #—
|
3.6 |
—
|
1,000,000 | — |
NEW
|
1,000,000 | $7,650,000 | 2024 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
ZURA
ZURA BIO LTD
|
Healthcare | 0.30% | — |
#22
Prev: #—
|
3.6 |
—
|
1,179,715 | — |
NEW
|
1,179,715 | $7,019,304 | 2026 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
PHAT
PHATHOM PHARMAC...
|
Healthcare | 0.29% | — |
#23
Prev: #—
|
3.6 |
—
|
625,000 | — |
NEW
|
625,000 | $6,943,750 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MREO
MEREO BIOPHARMA...
|
Healthcare | 0.19% | 0.15% |
#24
3
Prev: #27
|
3.1 |
—
|
5,512,389 | 70.2% |
P
S
|
13,368,855 | $4,411,722 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
STOK
STOKE THERAPEUT...
|
Healthcare | 0.14% | — |
#25
Prev: #—
|
3.6 |
—
|
100,000 | — |
NEW
|
100,000 | $3,256,000 | 2026 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
PRLD
PRELUDE THERAPE...
|
Healthcare | 0.14% | — |
#26
Prev: #—
|
3.6 |
—
|
947,049 | — |
NEW
|
947,049 | $3,238,908 | 2023 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
IBIO
IBIO INC
|
Healthcare | 0.13% | 0.20% |
#27
1
Prev: #26
|
0.1 |
—
|
-645,000 | -28.9% |
P
S
|
1,583,000 | $3,007,700 | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
N/A
HELIX ACQUISITI...
|
|
Unknown | 0.09% | — |
#28
Prev: #—
|
3.5 |
—
|
200,000 | — |
NEW
|
200,000 | $2,032,000 | — | 13F Filing | 2026-03-31 | 2026-05-15 | ||
|
ATRA
ATARA BIOTHERAP...
|
Healthcare | 0.02% | 0.47% |
#29
7
Prev: #22
|
0.0 |
—
|
-473,590 | -82.6% |
P
S
|
99,593 | $471,075 | 2024 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
SRZNW
SURROZEN INC
|
Unknown | 0.01% | 0.00% |
#30
Prev: #30
|
1.0 |
—
|
no change | no change |
P
S
|
4,444 | $129,454 | 2021 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
XNCR
CALL
XENCOR INC
|
CALL Option | 0.00% | 0.05% |
Sold All 😨
(Was: #29) |
0.0 |
—
|
-67,500 | -100.0% |
CLOSED
|
— | $— | 2016 Q2 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CAMP
CAMP4 THERAPEUT...
|
Healthcare | 0.00% | 0.09% |
Sold All 😨
(Was: #28) |
0.0 |
—
|
-325,000 | -100.0% |
CLOSED
|
— | $— | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
EOLS
EVOLUS INC
|
Healthcare | 0.00% | 0.20% |
Sold All 😨
(Was: #25) |
0.0 |
—
|
-675,000 | -100.0% |
CLOSED
|
— | $— | 2019 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
NUVB/WS
NUVATION BIO IN...
|
Unknown | 0.00% | 0.39% |
Sold All 😨
(Was: #24) |
0.0 |
—
|
-963,333 | -100.0% |
CLOSED
|
— | $— | 2021 Q1 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
MNKD
MANNKIND CORP
|
Healthcare | 0.00% | 0.43% |
Sold All 😨
(Was: #23) |
0.0 |
—
|
-1,660,000 | -100.0% |
CLOSED
|
— | $— | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
CGON
CALL
CG ONCOLOGY INC
|
CALL Option | 0.00% | 0.55% |
Sold All 😨
(Was: #21) |
0.0 |
—
|
-292,800 | -100.0% |
CLOSED
|
— | $— | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
VYGR
VOYAGER THERAPE...
|
Healthcare | 0.00% | 0.71% |
Sold All 😨
(Was: #20) |
0.0 |
—
|
-4,002,847 | -100.0% |
CLOSED
|
— | $— | 2021 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
AQST
AQUESTIVE THERA...
|
Healthcare | 0.00% | 0.77% |
Sold All 😨
(Was: #19) |
0.0 |
—
|
-2,625,000 | -100.0% |
CLOSED
|
— | $— | 2025 Q3 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
PCVX
VAXCYTE INC
|
Healthcare | 0.00% | 0.94% |
Sold All 😨
(Was: #18) |
0.0 |
—
|
-450,000 | -100.0% |
CLOSED
|
— | $— | 2021 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
GPCR
STRUCTURE THERA...
|
Healthcare | 0.00% | 1.06% |
Sold All 😨
(Was: #17) |
0.0 |
—
|
-334,380 | -100.0% |
CLOSED
|
— | $— | 2025 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 | |||
|
IMNM
IMMUNOME INC
|
Healthcare | 0.00% | 2.78% |
Sold All 😨
(Was: #8) |
0.0 |
—
|
-2,855,590 | -100.0% |
CLOSED
|
— | $— | 2023 Q4 | 13F Filing | 2026-03-31 | 2026-05-15 |
Showing 1-41 of 41 holdings