Arkolith/Funds/Brightline Capital Management, LLC

Brightline Capital Management, LLC

CIK 1432450
Holdings as of Mar 31, 2026·disclosed May 15, 2026·~45-day 13F lag·13F-HR
Active Filer

Brightline Capital Management, LLC holds a concentrated book of 9 stocks worth $338.1M as of Q1 2026 (disclosed May 15, 2026, a ~45-day 13F lag). This quarter they opened Regal Rexnord Corp. Their largest long position is Viasat Inc at 28% of the equity book. Cloning the disclosed picks since 2018 would be +263% (+16.4%/yr). That is a simulation of the disclosed long book, not audited returns.

Build

Build on this 13F portfolio

The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.

Build

Ask your agent what Brightline Capital Management, LLC owns

This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/funds/1432450/holdings"
Ask your agent
Use Arkolith to show BRIGHTLINE CAPITAL MANAGEMENT, LLC's latest
holdings, largest changes, and filing provenance.
Opened
2
new positions
Added to
7
existing
Trimmed
0
reduced
Sold out
1
exited

Growth of $10,000: cloning the disclosed book

If you'd copied them
+263.4%
+16.4%/yr · since Feb '18
Their reported book
+360.8%
held from quarter-end
S&P 500
+234.1%
same window
$4K$13K$23K$32K$41KFeb '18Sep '19Jul '21Feb '23Jan '25Aug '26
Brightline Capital Management, LLC (copied at disclosure) S&P 500

The reported book (valued from quarter-end) returned +360.8%, a 97.4-point gap that is the cost of the ~45-day 13F disclosure lag a real follower can't avoid.

Growth of $10,000 cloning Brightline Capital Management, LLC's disclosed long 13F book, rebalanced on each filing date (so it reflects each quarter's actual reporting lag, ~45 days for the latest filing, with no look-ahead), total-return basis (dividends reinvested), derived from end-of-day prices. “Their reported book” values the same picks from quarter-end, before they were public. S&P 500 is SPY total return over the same window. Excludes shorts, cash, options and non-13F holdings. Not investment advice.

Concentration

Top-heavy: concentrated book

Top 5 holdings
75%
Top 10 holdings
100%
Top 20 holdings
100%

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

Direct sector allocation

100% mapped to company sectors

Materials
34%
Communication Services
28%
Industrials
26%
Consumer Discretionary
11%

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

Funds with the most overlap

Other tracked managers holding the same core names as Brightline Capital Management, LLC

Manager / fundShared namesTheir $ in those
BlackRock, Inc.10 / 9$5.1B
VANGUARD CAPITAL MANAGEMENT LLC10 / 9$1.8B
GEODE CAPITAL MANAGEMENT, LLC10 / 9$1.0B
MORGAN STANLEY10 / 9$641.0M
Nuveen, LLC10 / 9$613.5M
CHARLES SCHWAB INVESTMENT MANAGEMENT INC10 / 9$492.2M
UBS Group AG10 / 9$448.8M
GOLDMAN SACHS GROUP INC10 / 9$393.9M

Ranked by how many of Brightline Capital Management, LLC's top 9 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.

Holdings: largest first

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

9 positions
#SecurityValueShares% PortLast moveHistory
1Viasat Inc
COM
$96.2M2.10M
28.4%
+0.3%
Added · +6K sh
2Constellium SE
CL A SHS
$45.4M1.85M
13.4%
+0.3%
Added · +5K sh
3Dana Inc
COM
$38.7M1.15M
11.4%
+0.3%
Added · +4K sh
4Amentum Holdings Inc
COM
$36.4M1.40M
10.8%
+0.3%
Added · +4K sh
5Ecovyst Inc
COM
$36.0M2.80M
10.6%
+37%
Added · +750K sh
6Fluor Corp New
COM
$28.0M601.0K
8.3%
+7.5%
Added · +42K sh
7Regal Rexnord Corporation
COM
$23.4M125.0K
6.9%
New
New position
8Kaiser Aluminum Corp
COM PAR $0.01
$21.1M175.0K
6.2%
+4.2%
Added · +7K sh
9Taseko Mines Ltd
COM
$12.9M2.00M
3.8%
New
New position
Showing all 9 positions

Filing history

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

QuarterAs ofFiledPositionsValueForm
Q1 2026Mar 31, 2026May 15, 20269$338.1M13F-HR
Q4 2025Dec 31, 2025Feb 13, 20268$247.4M13F-HR
Q3 2025Sep 30, 2025Nov 13, 202510$244.0M13F-HR
Q2 2025Jun 30, 2025Aug 14, 202515$232.2M13F-HR
Q1 2025Mar 31, 2025May 14, 202512$115.3M13F-HR
Q4 2024Dec 31, 2024Feb 13, 202513$145.8M13F-HR
Q3 2024Sep 30, 2024Nov 13, 202420$236.8M13F-HR
Q2 2024Jun 30, 2024Aug 13, 202419$201.5M13F-HR
Q1 2024Mar 31, 2024May 14, 202415$166.2M13F-HR
Q4 2023Dec 31, 2023Feb 14, 202410$92.2M13F-HR
Q3 2023Sep 30, 2023Oct 31, 20234$24.4M13F-HR
Q2 2023Jun 30, 2023Aug 11, 20231$8.7M13F-HR
Q1 2023Mar 31, 2023May 5, 20231$013F-HR
Q4 2022Dec 31, 2022Feb 3, 20235$45.4M13F-HR
Q3 2022Sep 30, 2022Nov 9, 20225$49.7M13F-HR
Q2 2022Jun 30, 2022Aug 3, 20224$43.1M13F-HR
Q1 2022Mar 31, 2022May 12, 20229$143.1M13F-HR
Q4 2021Dec 31, 2021Feb 7, 202213$162.8M13F-HR
Q3 2021Sep 30, 2021Nov 8, 202112$139.8M13F-HR
Q2 2021Jun 30, 2021Aug 9, 202111$148.6M13F-HR
Q1 2021Mar 31, 2021May 12, 202113$148.2M13F-HR
Q4 2020Dec 31, 2020Feb 9, 202115$132.5M13F-HR
Q3 2020Sep 30, 2020Nov 10, 202011$82.4M13F-HR
Q2 2020Jun 30, 2020Aug 4, 20206$26.4M13F-HR

Data source

Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 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. The performance line is a simulation of the disclosed long book, not an audited return.