Arkolith/Funds/Magnetar Financial LLC

Magnetar Financial LLC

CIK 1352851
Holdings as of Mar 31, 2026·disclosed May 13, 2026·~43-day 13F lag·13F-HR
Active Filer

Magnetar Financial LLC holds a focused book of 1129 stocks worth $9.8B as of Q1 2026 (disclosed May 13, 2026, a ~45-day 13F lag). This quarter they opened Penumbra Inc and trimmed Air Lease Corp. Their largest long position is Coreweave Inc-CL A at 48% of the equity book. They also disclosed $13.8M in put options (a bearish bet), shown separately below and excluded from the equity book.

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Use Arkolith to show Magnetar Financial LLC's latest
holdings, largest changes, and filing provenance.
Opened
607
new positions
Added to
147
existing
Trimmed
173
reduced
Sold out
360
exited

Concentration

Top-heavy: focused book

Top 5 holdings
52%
Top 10 holdings
56%
Top 20 holdings
63%

Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.

Direct sector allocation

88% mapped to company sectors

Information Technology
51%
Financials
22%
ETF / fund or unclassified
12%
Industrials
4%
Materials
3%
Health Care
2%
Utilities
2%
Communication Services
1%

Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.

Biggest moves: latest quarter

Estimated $ traded · quarter-end prices, no cost basis

Bought
Trimmed / exited

Holdings: largest first

Bars show each stock's share of the portfolio. Click a row for its position history.

1,129 positions
#SecurityValueShares% PortLast moveHistory
1Coreweave Inc
COM CL A
$4.7B68.57M
48.2%
+0.5%
Added · +375K sh
2Air Lease Corp
CL A
$87.2M1.34M
0.9%
−15%
Reduced · −245K sh
3Chart Inds Inc
COM
$86.9M420.4K
0.9%
−16%
Reduced · −81K sh
4TXNM Energy Inc
COM
$86.2M1.48M
0.9%
−13%
Reduced · −224K sh
5Penumbra Inc
COM
$82.6M251.4K
0.8%
New
New position
6Warner Bros Discovery Inc
COM SER A
$81.7M3.02M
0.8%
−5.2%
Reduced · −166K sh
7Proassurance Corp
COM
$80.3M3.25M
0.8%
−6.8%
Reduced · −238K sh
8Kenvue Inc
COM
$79.4M4.61M
0.8%
−13%
Reduced · −658K sh
9Webster Finl Corp
COM
$78.9M1.14M
0.8%
150×
Added · +1.1M sh
10Allied Gold Corp
COM NEW
$78.1M2.52M
0.8%
New
New position
11Norfolk Southn Corp
COM
$77.7M275.2K
0.8%
−20%
Reduced · −69K sh
12Teck Resources Ltd
CL B
$77.5M1.50M
0.8%
−20%
Reduced · −384K sh
13Masimo Corp
COM
$76.0M427.1K
0.8%
78×
Added · +422K sh
14Jd.com Inc
NOTE 0.250% 6/0
$74.6M74.69M
0.8%
+27%
Added · +15.9M sh
15Trip Com Group Ltd
NOTE 0.750% 6/1
$71.6M69.42M
0.7%
+11%
Added · +7.0M sh
16Digitalbridge Group Inc
CL A NEW
$65.0M4.22M
0.7%
+91%
Added · +2.0M sh
17CSG Sys Intl Inc
COM
$64.5M807.4K
0.7%
+0.4%
Added · +3K sh
18PG&E Corp
NOTE 4.250%12/0
$61.3M59.02M
0.6%
+57%
Added · +21.5M sh
19Hewlett Packard Enterprise C
7.625 MAND CONV
$60.3M925.0K
0.6%
+85%
Added · +425K sh
20Microchip Technology Inc.
DEP SHS REPSTG
$58.9M1.02M
0.6%
New
New position
21Amicus Therapeutic
COM
$57.6M3.99M
0.6%
+0.5%
Added · +18K sh
22Tri Pointe Homes Inc
COM
$55.5M1.19M
0.6%
18×
Added · +1.1M sh
23Silicon Laboratories Inc
COM
$51.2M245.8K
0.5%
New
New position
24Essential Utils Inc
COM
$48.5M1.20M
0.5%
+0.4%
Added · +5K sh
25Valaris Ltd
CL A
$47.8M487.3K
0.5%
61×
Added · +479K sh
26National Storage Affiliates
COM SHS BEN IN
$46.4M1.23M
0.5%
New
New position
27Alibaba Group Hldg Ltd
NOTE 0.500% 6/0
$45.5M32.74M
0.5%
−24%
Reduced · −10.5M sh
28Arcellx Inc
COMMON STOCK
$45.3M394.9K
0.5%
New
New position
29Unifirst Corp Mass
COM
$43.2M171.9K
0.4%
New
New position
30Veeco Instrs Inc Del
COM
$42.9M1.27M
0.4%
−25%
Reduced · −425K sh
31Qorvo Inc
COM
$41.9M541.2K
0.4%
−0.3%
Reduced · −2K sh
32Thermon Group Hldgs Inc
COM
$38.2M758.0K
0.4%
New
New position
33Liberty Broadband Corp
COM SER C
$36.4M723.8K
0.4%
−1.9%
Reduced · −14K sh
34Apellis Pharmaceuticals Inc
COM
$35.0M869.2K
0.4%
New
New position
35Skywater Technology Inc
COM
$32.2M1.18M
0.3%
New
New position
36International Money Express
COM
$30.4M1.92M
0.3%
+0.4%
Added · +8K sh
37Oracle Corp
6.5 DEP CUM SR D
$29.8M650.0K
0.3%
New
New position
38Stellar Bancorp Inc
COM
$29.7M812.2K
0.3%
New
New position
39Cantaloupe Inc
COM
$29.0M2.68M
0.3%
−27%
Reduced · −974K sh
40Sun Ctry Airls Hldgs Inc
COM
$28.3M1.72M
0.3%
New
New position
41Churchill Cap Corp XI
CL A ORD SHS
$27.4M2.70M
0.3%
New
New position
42Drugs Made In Amer Acq II Co
USD ORD SHS
$26.9M2.70M
0.3%
Held
43Novanta Inc
UNIT 11/01/2028
$26.8M500.0K
0.3%
+400%
Added · +400K sh
44Eqv Ventures Ac Corp. II
ORD SHS CL A
$25.2M2.50M
0.3%
Held
45Titan Acquisition Corp
CL A
$22.7M2.20M
0.2%
Held
46NextEra Energy Inc
UNIT 02/15/2029
$22.6M450.0K
0.2%
New
New position
47Talkspace Inc
COM
$22.0M4.26M
0.2%
New
New position
48Rithm Ppty TR Inc
COM NEW SHS
$21.9M1.64M
0.2%
Held
49Launch Two Acquisition Corp.
ORD SHS CL A
$21.0M1.98M
0.2%
Held
50Launch One Acquisition Corp
SHS CLASS A
$20.9M1.95M
0.2%
Held
Showing 50 of 1,129 positions

Largest options & derivatives disclosed

Put / call positions from the 13F — totals include every disclosed option leg

Put notional (bearish)$13.8M
TypeUnderlyingNotional valueUnderlying shares
PUT · bearishISHARES RUSSELL 2000 ETFIWM$13.8M58K

13F filers disclose option positions at the market value of the underlying the contracts reference, not the premium paid. A put is a bearish bet (it gains if the stock falls); a call is bullish. “Underlying shares” is the share count the contracts control, not a share holding. These legs are excluded from the equity book, weighting, concentration and sector figures above.

Filing history

As-of date vs the date the SEC received each filing

QuarterAs ofFiledPositionsValueForm
Q1 2026Mar 31, 2026May 13, 20261,755$9.8B13F-HR
Q4 2025Dec 31, 2025Feb 17, 20261,486$10.2B13F-HR
Q3 2025Sep 30, 2025Nov 13, 20251,474$16.5B13F-HR
Q2 2025Jun 30, 2025Aug 12, 20251,512$20.7B13F-HR
Q1 2025Mar 31, 2025May 15, 20251,329$7.6B13F-HR
Q4 2024Dec 31, 2024Feb 11, 2025942$4.4B13F-HR
Q3 2024Sep 30, 2024Nov 13, 2024829$4.6B13F-HR
Q2 2024Jun 30, 2024Aug 14, 2024497$4.8B13F-HR
Q1 2024Mar 31, 2024May 15, 2024363$4.5B13F-HR
Q4 2023Dec 31, 2023Feb 13, 2024363$3.9B13F-HR
Q3 2023Sep 30, 2023Nov 14, 2023435$3.9B13F-HR
Q2 2023Jun 30, 2023Aug 11, 2023476$4.6B13F-HR
Q1 2023Mar 31, 2023May 15, 2023597$5.1B13F-HR
Q4 2022Dec 31, 2022Feb 14, 2023767$5.9B13F-HR
Q3 2022Sep 30, 2022Nov 14, 20221,356$7.2B13F-HR
Q2 2022Jun 30, 2022Aug 15, 20221,661$9.7B13F-HR
Q1 2022Mar 31, 2022May 16, 20221,308$9.4B13F-HR
Q4 2021Dec 31, 2021Feb 14, 20221,351$10.0B13F-HR
Q3 2021Sep 30, 2021Jan 14, 20221,287$9.8B13F-HR/A
Q2 2021Jun 30, 2021Aug 6, 20211,173$10.6B13F-HR
Q1 2021Mar 31, 2021May 14, 20211,026$10.4B13F-HR
Q4 2020Dec 31, 2020Feb 12, 2021693$7.1B13F-HR
Q3 2020Sep 30, 2020Nov 16, 2020641$5.7B13F-HR
Amended / restated
  • Q3 2021 · filed Nov 12, 202113F-HR · superseded

Data source

Holdings from SEC EDGAR 13F-HR filings, updated quarterly ~45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.