Institutional HoldersBeta

Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.

CENTURY ALUMINUM CO

CIK 0000949157CENX· quarter ending 2026-06-30

Shares outstanding

98,993,295

as of 2026-08-04 · 10-Q cover page, filed 2026-08-06

Held by 13F filers

86,228,000

selection includes debt or preferreds — no % of shares outstanding

Holders

+0 vs 2026-03-31 · 1 new, 1 exited

Value

$216.6M

shares +0.1% vs prior quarter

13F holdings exceed the share count. This is normal for heavily shorted stocks: shares lent to short sellers are reported by the lender and again by whoever bought them. Related filers occasionally report the same position twice as well.

Share classes (cover page of the 10-Q filed 2026-08-06, as of 2026-08-04)

Class	Listed	Shares outstanding	Held by 13F filers	% of class	Holders	CUSIP
Common stock	CENX · NASDAQ	98,993,295	105,989,390	107.1%	416	156431108

Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.

Securities (CUSIPs held in 13F this quarter)

tick to combine

Count	CUSIP	Class (as filers write it)	Holders	Shares held	Class shares	% of class	Value	Options	Mapped via
	156431108	COM	416	105,989,390	98,993,295	107.1%	$5.0B	17 call / 9 put	13DG	holders →
	156431AQ1	NOTE 2.750% 5/0not common	12	6,938,000 $79.3M principal	—	—	$216.6M	—	NPORT	holders →

Totals combine the ticked CUSIPs and update as you tick: common-stock classes by default; preferreds, notes, warrants and depositary shares are listed but not counted. "holders →" shows a single CUSIP on its own. Bonds are held as a principal amount, not shares. Options positions are never counted as holdings. 2 further CUSIPs map to this company (mostly bonds) but no 13F filer held them this quarter.

Top holders (12 of 12 · 156431AQ1)

change vs 2026-03-31

#	Filer	Shares / principal	% of class	Value	Change
1	Context Capital Management, LLC	34,817,000	—	$86.0M	-5,000,000 (-12.6%)
2	D. E. Shaw & Co., Inc.	13,512,000	—	$33.4M	—
3	READYSTATE ASSET MANAGEMENT LP	12,070,000	—	$29.8M	—
4	ABSOLUTE INVESTMENT ADVISERS, LLC	6,938,000	—	$17.1M	+1,288,000 (+22.8%)
5	SILVERBACK ASSET MANAGEMENT LLC	5,000,000	—	$12.3M	NEW
6	BANK OF MONTREAL /CAN/	3,750,000	—	$11.2M	—
7	LORD, ABBETT & CO. LLC	3,634,000	—	$9.0M	+832,000 (+29.7%)
8	WELLS FARGO & COMPANY/MN	3,407,000	—	$10.2M	-832,000 (-19.6%)
9	FMR LLC	1,250,000	—	$3.1M	—
10	Warberg Asset Management LLC	1,000,000	—	$2.5M	+812,000 (+431.9%)
11	AGF MANAGEMENT LTD	600,000	—	$1.5M	-100,000 (-14.3%)
12	Purpose Unlimited Inc.	250,000	—	$617K	—

Exited since 2026-03-31 (1 filers; largest 1 shown)

SSI INVESTMENT MANAGEMENT LLC

−1,900,000

Large holders from 13D/13G (latest per reporting person, last 2 years)

Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.

Reporting person	Form	Filed	Event	Shares	% of class
BlackRock, Inc.	SCHEDULE 13G/A	2026-10-05	2026-09-30	10,395,973	10.5%
STATE STREET CORPORATION	SCHEDULE 13G	2026-08-07	2026-06-30	5,542,720	5.6%
The Vanguard Group	SCHEDULE 13G/A	2026-03-26	2026-03-13	0	0%
Glencore AG	SCHEDULE 13D/A	2026-03-04	2026-03-04	17,505,947	17.68%
Glencore International AG	SCHEDULE 13D/A	2026-03-04	2026-03-04	29,690,702	29.99%
Glencore plc	SCHEDULE 13D/A	2026-03-04	2026-03-04	29,690,702	29.99%

Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.