Vault-13

ARCELLX INC ACLX

COMMON STOCK · Common Stock · CUSIP 03940C100

158 institutional holders +20 vs Q3 2023
49,116,88649.1m shares reported held*
$2.7bnreported value*
26 new 59 added 47 reduced 17 sold out net bought ≈ $6.9m (+124.0k shares)

* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($5.1m this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $55.50. Options: 10 managers hold calls ($22.5m notional), 8 hold puts ($8.7m).

Trends to Q4 2023

Institutional holders

Managers reporting a position, each quarter

0100200Q3 22: 74Q4 22: 127Q1 23: 119Q2 23: 140Q3 23: 138Q4 23: 158158Q3 22Q4 22Q1 23Q2 23Q3 23Q4 23
Numbers
QuarterHolders
Q3 202274
Q4 2022127
Q1 2023119
Q2 2023140
Q3 2023138
Q4 2023158

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
1000100Q4 22: 86 bought or addedQ4 22: 32 cut or sold outQ4 22Q1 23: 61 bought or addedQ1 23: 63 cut or sold outQ1 23Q2 23: 99 bought or addedQ2 23: 44 cut or sold outQ2 23Q3 23: 75 bought or addedQ3 23: 57 cut or sold outQ3 23Q4 23: 85 bought or addedQ4 23: 64 cut or sold outQ4 23
Numbers
QuarterBought or addedCut or sold out
Q4 20228632
Q1 20236163
Q2 20239944
Q3 20237557
Q4 20238564

Calls vs puts

Options held, notional value, last 4 quarters. P/C = puts ÷ calls

CallsPuts
$0$10m$20m$30mQ1 23 calls: $1.1mQ1 23 puts: $1.2mQ1 23P/C 1.06Q2 23 calls: $1.0mQ2 23 puts: $1.7mQ2 23P/C 1.68Q3 23 calls: $846.8kQ3 23 puts: $190.2kQ3 23P/C 0.22Q4 23 calls: $22.5mQ4 23 puts: $8.7mQ4 23P/C 0.38
Numbers
QuarterCallsPutsP/C
Q1 2023$1.1m$1.2m1.06
Q2 2023$1.0m$1.7m1.68
Q3 2023$846.8k$190.2k0.22
Q4 2023$22.5m$8.7m0.38

Biggest buyers

MORGAN STANLEY Added +1,241,312+1.2m
Deep Track Capital, LP New +725,145+725.1k
Paradigm Biocapital Advisors LP Added +705,502+705.5k
JPMORGAN CHASE & CO Added +639,927+639.9k
PERCEPTIVE ADVISORS LLC Added +578,831+578.8k
PRICE T ROWE ASSOCIATES INC /MD/ Added +323,309+323.3k
BlackRock Inc. Added +310,876+310.9k
LORD, ABBETT & CO. LLC Added +197,060+197.1k
Integral Health Asset Management, LLC New +160,000+160.0k
FEDERATED HERMES, INC. Added +143,212+143.2k

Biggest sellers

NOVO HOLDINGS A/S Sold out -1,075,000-1.1m
SR One Capital Management, LP Reduced -800,000-800.0k
GOLDMAN SACHS GROUP INC Reduced -519,165-519.2k
Vivo Capital, LLC Sold out -503,565-503.6k
Soleus Capital Management, L.P. Reduced -484,777-484.8k
Cormorant Asset Management, LP Reduced -450,000-450.0k
MONTANOVA CAPITAL, LLC Reduced -433,993-434.0k
Pictet Asset Management Holding SA Reduced -329,875-329.9k
STATE STREET CORP Reduced -240,406-240.4k
GREAT POINT PARTNERS LLC Reduced -239,236-239.2k

Biggest calls

JANE STREET GROUP, LLC New $7.4m132.9k shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Added $5.4m97.7k shares
SIMPLEX TRADING, LLC New $2.6m47.1k shares
JPMORGAN CHASE & CO New $2.1m38.4k shares
CITADEL ADVISORS LLC Added $1.8m32.5k shares
Caption Management, LLC New $1.4m25.0k shares
GROUP ONE TRADING LLC Added $1.2m21.7k shares
Squarepoint Ops LLC New $305.2k5.5k shares
STEMPOINT CAPITAL LP First filing $283.5k623 shares
CONCOURSE FINANCIAL GROUP SECURITIES, INC. Unchanged $00 shares

Biggest puts

JANE STREET GROUP, LLC New $4.1m73.8k shares
SIMPLEX TRADING, LLC New $2.0m35.7k shares
Caption Management, LLC New $1.4m25.0k shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP New $477.3k8.6k shares
CITADEL ADVISORS LLC Added $382.9k6.9k shares
BARCLAYS PLC New $277.5k5.0k shares
GROUP ONE TRADING LLC New $55.5k1.0k shares
CONCOURSE FINANCIAL GROUP SECURITIES, INC. Unchanged $00 shares

Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.

Major shareholders (over 5%)

Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.

HolderStakeChangeShares Last filed
GILEAD SCIENCES, INC. 13D · may seek influence +88.5 pts · filed 2026-04-28
Stated purposeItem 4 of the Original Schedule 13D is amended to include the following at the end thereof: "As previously disclosed, Gilead, Purchaser and Arcellx entered into the Merger Agreement pursuant to which Purchaser commenced the Offer on March 6, 2026. The Offer expired at 5:00 p.m., Eastern Time, on April 27, 2026. Computershare Trust Company N.A., the depositary and paying agent for the Offer, advised Gilead that, as of the expiration of the Offer, 38,795,604 Shares had been validly tendered and not validly withdrawn pursuant to the Offer, representing, together with Shares already owned by Gilead, approximately 77.2% of the Shares outstanding as of the expiration of the Offer. Following consummation of the Offer, on April 28, 2026, Gilead completed its acquisition of Arcellx through the m… Full filing
 100.0% +88.5 pts 100 2026-04-28
BlackRock, Inc. 13G · institution filed 2025-04-17 6.4% 3.5m 2025-04-17

Fell to 5% or below in the last year: Paradigm Biocapital Advisors LP (0.0%, 2026-08-14), Vestal Point Capital, LP (0.0%, 2026-05-15), New Enterprise Associates 15, L.P. (0.0%, 2026-04-30), Elghandour Rami (0.0%, 2026-04-28), VANGUARD GROUP INC (0.0%, 2026-03-26), T. Rowe Price Investment Management, Inc. (4.5%, 2026-03-06), FMR LLC (0.5%, 2026-03-06), RA CAPITAL MANAGEMENT, L.P. (2.2%, 2026-02-17)

Holders, Q4 2023

#ManagerLocationShares Value% of their portfolioChangeShares change
1 PERCEPTIVE ADVISORS LLC 5.64% of their portfolio NEW YORK, NY 4,544,8094.5m $252.2m $252.2m 5.64% Added +578.8k +578,831
2 FMR LLC 0.02% of their portfolio BOSTON, MA 4,379,1694.4m $243.0m $243.0m 0.02% Reduced -158.2k -158,183
3 NEA Management Company, LLC 13.85% of their portfolio TIMONIUM, MD 3,745,2623.7m $207.9m $207.9m 13.85% Unchanged
4 Paradigm Biocapital Advisors LP 9.52% of their portfolio NEW YORK, NY 3,658,6243.7m $203.1m $203.1m 9.52% Added +705.5k +705,502
5 SR One Capital Management, LP 73.33% of their portfolio Redwood City, CA 3,146,6303.1m $174.6m $174.6m 73.33% Reduced -800.0k -800,000
6 BlackRock Inc. 0.00% of their portfolio New York, NY 3,018,5383.0m $167.5m $167.5m 0.00% Added +310.9k +310,876
7 MONTANOVA CAPITAL, LLC 6.18% of their portfolio New York, NY 2,435,9742.4m $135.2m $135.2m 6.18% Reduced -434.0k -433,993
8 LORD, ABBETT & CO. LLC 0.24% of their portfolio JERSEY CITY, NJ 2,393,1342.4m $132.8m $132.8m 0.24% Added +197.1k +197,060
9 VANGUARD GROUP INC 0.00% of their portfolio Valley Forge, PA 2,061,8192.1m $114.4m $114.4m 0.00% Added +23.3k +23,262
10 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 1,773,8391.8m $98.4m $98.4m 0.00% Reduced -240.4k -240,406
11 Cormorant Asset Management, LP 4.52% of their portfolio BOSTON, MA 1,700,0001.7m $94.3m $94.3m 4.52% Reduced -450.0k -450,000
12 JANUS HENDERSON GROUP PLC 0.05% of their portfolio LONDON, X0 1,538,2101.5m $85.4m $85.4m 0.05% Reduced -237.2k -237,228
13 MORGAN STANLEY 0.00% of their portfolio NEW YORK, NY 1,346,5701.3m $74.7m $74.7m 0.00% Added +1.2m +1,241,312
14 PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio BALTIMORE, MD 1,260,1801.3m $69.9m $69.9m 0.01% Added +323.3k +323,309
15 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 1,203,8261.2m $66.8m $66.8m 0.00% Added +639.9k +639,927
16 T. Rowe Price Investment Management, Inc. 0.03% of their portfolio BALTIMORE, MD 922,399922.4k $51.2m $51.2m 0.03% Added +12.2k +12,221
17 GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio BOSTON, MA 785,402785.4k $43.6m $43.6m 0.00% Added +46.3k +46,348
18 Deep Track Capital, LP 1.41% of their portfolio GREENWICH, CT 725,145725.1k $40.2m $40.2m 1.41% New
19 SAMSARA BIOCAPITAL, LLC 3.98% of their portfolio PALO ALTO, CA 460,441460.4k $25.6m $25.6m 3.98% Reduced -153.5k -153,480
20 NORTHERN TRUST CORP 0.00% of their portfolio CHICAGO, IL 363,421363.4k $20.2m $20.2m 0.00% Reduced -4.0k -4,030
21 GOLDMAN SACHS GROUP INC 0.00% of their portfolio NEW YORK, NY 355,693355.7k $19.7m $19.7m 0.00% Reduced -519.2k -519,165
22 Affinity Asset Advisors, LLC 3.76% of their portfolio NEW YORK, NY 340,000340.0k $18.9m $18.9m 3.76% Reduced -60.0k -60,000
23 PFM Health Sciences, LP 1.12% of their portfolio SAN FRANCISCO, CA 335,198335.2k $18.6m $18.6m 1.12% Added +94.9k +94,860
24 ADAGE CAPITAL PARTNERS GP, L.L.C. 0.04% of their portfolio Boston, MA 332,904332.9k $18.5m $18.5m 0.04% Reduced -60.0k -60,000
25 STEMPOINT CAPITAL LP 5.00% of their portfolio NEW YORK, NY 313,604313.6k $17.4m $17.4m 5.00% First filing
26 Candriam S.C.A. 0.11% of their portfolio STRASSEN, N4 282,013282.0k $15.7m $15.7m 0.11% Reduced -116.0k -116,007
27 Nuveen Asset Management, LLC 0.00% of their portfolio CHICAGO, IL 279,626279.6k $15.5m $15.5m 0.00% Added +35.4k +35,433
28 CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio SAN FRANCISCO, CA 264,178264.2k $14.7m $14.7m 0.00% Added +3.7k +3,722
29 VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.05% of their portfolio JUPITER, FL 235,760235.8k $13.1m $13.1m 0.05% Added +132.7k +132,709
30 FEDERATED HERMES, INC. 0.03% of their portfolio PITTSBURGH, PA 214,599214.6k $11.9m $11.9m 0.03% Added +143.2k +143,212
31 BANK OF AMERICA CORP /DE/ 0.00% of their portfolio CHARLOTTE, NC 194,287194.3k $10.8m $10.8m 0.00% Added +84.8k +84,841
32 Russell Investments Group, Ltd. 0.02% of their portfolio Seattle, WA 189,542189.5k $10.5m $10.5m 0.02% Added +11.2k +11,200
33 Parkman Healthcare Partners LLC 1.32% of their portfolio STAMFORD, CT 168,262168.3k $9.3m $9.3m 1.32% Reduced -35.2k -35,220
34 Integral Health Asset Management, LLC 1.28% of their portfolio New York, NY 160,000160.0k $8.9m $8.9m 1.28% New
35 Soleus Capital Management, L.P. 0.98% of their portfolio GREENWICH, CT 159,000159.0k $8.8m $8.8m 0.98% Reduced -484.8k -484,777
36 VICTORY CAPITAL MANAGEMENT INC 0.01% of their portfolio San Antonio, TX 155,652155.7k $8.6m $8.6m 0.01% Added +126.0k +126,002
37 TWO SIGMA INVESTMENTS, LP 0.02% of their portfolio NEW YORK, NY 145,274145.3k $8.1m $8.1m 0.02% Added +3.2k +3,178
38 DEUTSCHE BANK AG\ 0.00% of their portfolio FRANKFURT AM MAIN, 2M 139,187139.2k $7.7m $7.7m 0.00% Added +120.1k +120,097
39 Bank of New York Mellon Corp 0.00% of their portfolio NEW YORK, NY 131,934131.9k $7.3m $7.3m 0.00% Added +14.7k +14,666
40 UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio NEW YORK, NY 130,136130.1k $7.2m $7.2m 0.00% Reduced -55.5k -55,457
41 BARCLAYS PLC 0.00% of their portfolio LONDON, X0 129,426129.4k $7.2m $7.2m 0.00% Added +43.2k +43,239
42 Squarepoint Ops LLC 0.03% of their portfolio NEW YORK, NY 129,156129.2k $7.2m $7.2m 0.03% New
43 Cubist Systematic Strategies, LLC 0.09% of their portfolio STAMFORD, CT 127,058127.1k $7.1m $7.1m 0.09% New
44 CAAS CAPITAL MANAGEMENT LP 6.58% of their portfolio NEW YORK, NY 124,959125.0k $6.9m $6.9m 6.58% Unchanged
45 Walleye Capital LLC 0.09% of their portfolio NEW YORK, NY 118,335118.3k $6.6m $6.6m 0.09% Reduced -97.9k -97,935
46 Rafferty Asset Management, LLC 0.03% of their portfolio New York, NY 111,952112.0k $6.2m $6.2m 0.03% Reduced -46.8k -46,826
47 Woodline Partners LP 0.06% of their portfolio San Francisco, CA 104,060104.1k $5.8m $5.8m 0.06% New
48 UBS Group AG 0.00% of their portfolio ZURICH, V8 97,04597.0k $5.4m $5.4m 0.00% Added +47.6k +47,613
49 JANE STREET GROUP, LLC 0.01% of their portfolio NEW YORK, NY 84,39184.4k $4.7m $4.7m 0.01% Added +74.5k +74,486
50 VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio ATLANTA, GA 81,47281.5k $4.5m $4.5m 0.00% Added +24.3k +24,320
51 TD Asset Management Inc 0.00% of their portfolio Toronto, A6 81,31881.3k $4.5m $4.5m 0.00% Reduced -282 -282
52 ACUTA CAPITAL PARTNERS, LLC 2.41% of their portfolio REDWOOD CITY, CA 77,00077.0k $4.3m $4.3m 2.41% New
53 HighVista Strategies LLC 1.45% of their portfolio BOSTON, MA 72,23072.2k $4.0m $4.0m 1.45% Reduced -5.8k -5,798
54 D. E. Shaw & Co., Inc. 0.01% of their portfolio New York, NY 67,07467.1k $3.7m $3.7m 0.01% New
55 Informed Momentum Co LLC 0.64% of their portfolio SOLANA BEACH, CA 65,05265.1k $3.6m $3.6m 0.64% New
56 BAMCO INC /NY/ 0.01% of their portfolio NEW YORK, NY 63,50063.5k $3.5m $3.5m 0.01% Added +13.5k +13,500
57 TWINBEECH CAPITAL LP 0.06% of their portfolio PURCHASE, NY 63,46463.5k $3.5m $3.5m 0.06% New
58 RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio NEW YORK, NY 61,10061.1k $3.4m $3.4m 0.01% Added +7.3k +7,300
59 Vestal Point Capital, LP 0.35% of their portfolio NEW YORK, NY 60,00060.0k $3.3m $3.3m 0.35% First filing
60 Pictet Asset Management Holding SA 0.00% of their portfolio CAROUGE, V8 58,24558.2k $3.2m $3.2m 0.00% Reduced -329.9k -329,875
61 MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio NEW YORK, NY 57,37457.4k $3.2m $3.2m 0.00% Added +6.0k +6,009
62 Swiss National Bank 0.00% of their portfolio ZURICH, V8 57,20057.2k $3.2m $3.2m 0.00% Reduced -6.1k -6,100
63 CITIGROUP INC 0.00% of their portfolio NEW YORK, NY 52,33152.3k $2.9m $2.9m 0.00% Reduced -16.7k -16,685
64 RHUMBLINE ADVISERS 0.00% of their portfolio BOSTON, MA 51,43551.4k $2.9m $2.9m 0.00% Added +83 +83
65 GREAT POINT PARTNERS LLC 0.46% of their portfolio Greenwich, CT 48,26448.3k $2.7m $2.7m 0.46% Reduced -239.2k -239,236
66 MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio Toronto, A6 45,45145.5k $2.5m $2.5m 0.00% Added +12.3k +12,268
67 Schonfeld Strategic Advisors LLC 0.02% of their portfolio NEW YORK, NY 40,51040.5k $2.2m $2.2m 0.02% Reduced -15.8k -15,847
68 MYDA Advisors LLC 0.95% of their portfolio WOODMERE, NY 40,00040.0k $2.2m $2.2m 0.95% Added +15.0k +15,000
69 PUTNAM INVESTMENTS LLC 0.00% of their portfolio BOSTON, MA 39,31439.3k $2.2m $2.2m 0.00% Reduced -1.9k -1,942
70 CREDIT SUISSE AG/ 0.00% of their portfolio ZURICH, V8 37,18337.2k $2.1m $2.1m 0.00% Added +2.7k +2,704
71 ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio NASHVILLE, TN 37,00037.0k $2.1m $2.1m 0.00% Added +790 +790
72 Connor, Clark & Lunn Investment Management Ltd. 0.01% of their portfolio VANCOUVER, A1 36,98237.0k $2.1m $2.1m 0.01% Added +17.6k +17,618
73 ALPS ADVISORS INC 0.01% of their portfolio Denver, CO 32,40232.4k $1.8m $1.8m 0.01% Reduced -3.3k -3,308
74 CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio WEST SACRAMENTO, CA 32,15832.2k $1.8m $1.8m 0.00% Reduced -1.7k -1,666
75 STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio MADISON, WI 31,38131.4k $1.7m $1.7m 0.00% Added +3.7k +3,721
76 DekaBank Deutsche Girozentrale 0.00% of their portfolio FRANKFURT, 2M 30,00030.0k $1.7m $1.7m 0.00% Added +14.0k +14,000
77 Legal & General Group Plc 0.00% of their portfolio London, X0 29,76229.8k $1.7m $1.7m 0.00% Reduced -105 -105
78 SG Americas Securities, LLC 0.02% of their portfolio NEW YORK, NY 28,78528.8k $1.6m $1.6m 0.02% Added +11.7k +11,718
79 MARTINGALE ASSET MANAGEMENT L P 0.03% of their portfolio BOSTON, MA 27,13427.1k $1.5m $1.5m 0.03% Added +251 +251
80 FIRST TRUST ADVISORS LP 0.00% of their portfolio Wheaton, IL 25,50525.5k $1.4m $1.4m 0.00% Added +10.1k +10,088
81 CONGRESS ASSET MANAGEMENT CO 0.01% of their portfolio BOSTON, MA 25,05925.1k $1.4m $1.4m 0.01% Reduced -19 -19
82 Invesco Ltd. 0.00% of their portfolio ATLANTA, GA 24,99425.0k $1.4m $1.4m 0.00% Added +1.1k +1,064
83 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 23,19623.2k $1.3m $1.3m 0.00% Reduced -21.5k -21,500
84 SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio BALA CYNWYD, PA 23,08123.1k $1.3m $1.3m 0.00% Added +9.0k +8,981
85 Advantage Alpha Capital Partners LP 0.24% of their portfolio SAN FRANCISCO, CA 22,67322.7k $1.3m $1.3m 0.24% New
86 Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio SEOUL, M5 22,36722.4k $1.2m $1.2m 0.00% Reduced -1.2k -1,214
87 FORA Capital, LLC 0.11% of their portfolio MIAMI, FL 22,21722.2k $1.2m $1.2m 0.11% New
88 MetLife Investment Management, LLC 0.01% of their portfolio Whippany, NJ 20,18420.2k $1.1m $1.1m 0.01% Unchanged
89 AMERICAN INTERNATIONAL GROUP, INC. 0.00% of their portfolio New York, NY 19,06619.1k $1.1m $1.1m 0.00% Added +125 +125
90 PROFUND ADVISORS LLC 0.04% of their portfolio BETHESDA, MD 18,59718.6k $1.0m $1.0m 0.04% Reduced -8.3k -8,275
91 FRANKLIN RESOURCES INC 0.00% of their portfolio San Mateo, CA 18,24318.2k $1.0m $1.0m 0.00% Unchanged
92 Point72 Middle East FZE 0.07% of their portfolio DUBAI, C0 17,90317.9k $993.6k $993.6k 0.07% New
93 Allianz Asset Management GmbH 0.00% of their portfolio MUNICH, 2M 15,80015.8k $876.9k $876.9k 0.00% Added +7.5k +7,500
94 NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio ALBANY, NY 15,43815.4k $856.8k $856.8k 0.00% Reduced -62 -62
95 Entropy Technologies, LP 0.16% of their portfolio NEW YORK, NY 15,41615.4k $855.6k $855.6k 0.16% First filing
96 Jump Financial, LLC 0.03% of their portfolio Chicago, IL 15,18315.2k $842.7k $842.7k 0.03% New
97 WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio Boston, MA 14,06914.1k $780.8k $780.8k 0.00% Reduced -43.6k -43,565
98 Qube Research & Technologies Ltd 0.00% of their portfolio LONDON, X0 13,92513.9k $772.8k $772.8k 0.00% New
99 HRT FINANCIAL LP 0.01% of their portfolio NEW YORK, NY 12,72512.7k $706.0k $706.0k 0.01% Reduced -8.3k -8,290
100 HighTower Advisors, LLC 0.00% of their portfolio CHICAGO, IL 12,44712.4k $691.0k $691.0k 0.00% Added +39 +39