Arkolith/Funds/Mainstream Capital Management LLC

Mainstream Capital Management LLC

CIK 2043084
Holdings as of Jun 30, 2026·disclosed Jul 15, 2026·~15-day 13F lag·13F-HR
Active Filer

Mainstream Capital Management LLC holds a focused book of 90 reported positions worth $166.1M as of Q2 2026 (disclosed Jul 15, 2026, a ~15-day 13F lag). This quarter they opened Intl Business Machines Corp and trimmed JPMorgan Ultra-Short Income. Their largest long position is JPMorgan Ultra-Short Income at 12% of the reported non-option book. Cloning the disclosed picks since 2024 would be +24% (+12.3%/yr). That is a simulation of the disclosed long book, not audited returns.

Growth of $10,000: cloning the disclosed book

If you'd copied them
+24.0%
+12.3%/yr · since Oct '24
Their reported book
+24.9%
held from quarter-end
S&P 500
+37.9%
same window
$9K$10K$11K$13K$14KOct '24Mar '25Aug '25Dec '25Apr '26Sep '26
Mainstream Capital Management LLC (copied at disclosure) S&P 500

Growth of $10,000 cloning Mainstream Capital Management LLC's disclosed long 13F book, rebalanced on each filing date (so it reflects each quarter's actual reporting lag, ~15 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.

How much sits in the biggest positions

Top-heavy: focused book

Top 5 holdings
33%
Top 10 holdings
45%
Top 20 holdings
62%

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

Where the money is, by sector

61% mapped to company sectors

ETFs / funds
39%
Information Technology
28%
Consumer Discretionary
13%
Financials
10%
Industrials
4%
Materials
2%
Health Care
2%
Communication Services
1%

+3 sectors below the cut, 1% together

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 (an exit at the prior quarter-end), no cost basis

Bought
Trimmed / exited

Funds with the most overlap

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

Manager / fundShared namesTheir $ in those
Donor Advised Charitable Giving, Inc.8 / 80$4.5B
Hoffman, Alan N Investment Management10 / 80$162.3M
Swiss Re Ltd37 / 80$1.0B
Prospect Hill Management, LLC10 / 80$243.7M
Draper Asset Management, LLC11 / 80$181.0M
Greenbrier Partners Capital Management, LLC8 / 80$1.2B
Conway Capital Management, Inc.20 / 80$205.4M
New World Advisors LLC36 / 80$533.8M

Ranked by the share of each fund's own book sitting in the names it shares with Mainstream Capital Management LLC: only funds sharing at least a tenth of the book qualify. Index giants, bank custody books and market makers are excluded. They hold everything, so their overlap says nothing.

Holdings: largest first

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

90 positions
#SecurityValueShares% PortLast moveHistory
1JPMorgan Ultra-Short Income ETF
ETF
$20.3M402.2K
12.2%
−2.5%
Reduced · −10K sh
2Apple Inc Com
Stock
$9.9M34.1K
5.9%
−4.1%
Reduced · −1K sh
3Goldman Sachs Ultra Short Bond ETF
ETF
$9.5M187.4K
5.7%
+6.4%
Added · +11K sh
4Amazon Com Inc Com
Stock
$7.4M31.0K
4.4%
−0.6%
Reduced · −184 sh
5Alphabet Inc Cap STK CL C
Stock
$7.1M20.2K
4.3%
−0.1%
Reduced · −23 sh
6Nvidia Corporation Com
Stock
$5.5M27.6K
3.3%
−0.4%
Reduced · −120 sh
7Ishares Russell 1000 Growth ETF
ETF
$4.3M34.3K
2.6%
+294%
Added · +26K sh
8Meta Platforms Inc CL A
Stock
$4.2M7.5K
2.5%
−0.8%
Reduced · −62 sh
9Corning Inc Com
Stock
$3.6M14.3K
2.2%
+0.8%
Added · +108 sh
10Ishares Russell 1000 Value ETF
ETF
$3.5M14.6K
2.1%
−1.7%
Reduced · −248 sh
11Ishares Core S&P 500 ETF
ETF
$3.3M4.3K
2.0%
−1.9%
Reduced · −83 sh
12Alphabet Inc Cap STK CL A
Stock
$3.2M8.8K
1.9%
−2.4%
Reduced · −220 sh
13JPMorgan Chase & Co Com
Stock
$2.9M8.7K
1.7%
−0.2%
Reduced · −17 sh
14Berkshire Hathaway Inc Del CL B New
Stock
$2.7M5.4K
1.6%
+0.1%
Added · +4 sh
15Eli Lilly & Co Com
Stock
$2.7M2.3K
1.6%
−1.8%
Reduced · −42 sh
16Crowdstrike Hldgs Inc CL A
Stock
$2.6M3.5K
1.6%
−0.3%
Reduced · −12 sh
17Palo Alto Networks Inc Com
Stock
$2.6M7.7K
1.6%
−0.4%
Reduced · −28 sh
18State Street SPDR S&P 500 ETF
ETF
$2.6M3.5K
1.6%
Held
19Tesla Inc Com
Stock
$2.5M6.0K
1.5%
−0.1%
Reduced · −5 sh
20Advanced Micro Devices Inc Com
Stock
$2.3M4.0K
1.4%
+27%
Added · +859 sh
21Costco Wholesale Corporation Com
Stock
$2.2M2.3K
1.3%
−0.2%
Reduced · −5 sh
22SPDR Gold Shares
ETF
$2.1M5.6K
1.2%
−9.7%
Reduced · −600 sh
23Microsoft Corp Com
Stock
$2.0M5.4K
1.2%
+0.1%
Added · +5 sh
24Vanguard Information Technology ETF
ETF
$1.9M16.1K
1.2%
+699%
Added · +14K sh
25Goldman Sachs Group Inc Com
Stock
$1.9M1.9K
1.2%
−0.4%
Reduced · −7 sh
26Interactive Brokers Group Inc Com CL A
Stock
$1.9M21.9K
1.1%
+0.5%
Added · +109 sh
27Ge Vernova Inc Com
Stock
$1.9M1.6K
1.1%
+16%
Added · +225 sh
28TJX Cos Inc New Com
Stock
$1.9M12.3K
1.1%
+0.3%
Added · +33 sh
29International Business Machs Com
Stock
$1.9M6.6K
1.1%
New
New position
30Ishares Msci USA Quality Factor ETF
ETF
$1.8M8.2K
1.1%
−0.3%
Reduced · −21 sh
31Vanguard Mid-Cap Value ETF
ETF
$1.8M9.0K
1.1%
−0.1%
Reduced · −9 sh
32Vanguard Mid-Cap Growth ETF
ETF
$1.8M5.8K
1.1%
−0.3%
Reduced · −16 sh
33Cava Group Inc Com
Stock
$1.7M21.4K
1.0%
+0.3%
Added · +57 sh
34Netflix Inc. Com
Stock
$1.6M23.0K
1.0%
+0.1%
Added · +15 sh
35Toast Inc CL A
Stock
$1.6M56.8K
1.0%
−1.1%
Reduced · −610 sh
36Schwab Charles Corp Com
Stock
$1.5M16.0K
0.9%
−4.0%
Reduced · −663 sh
37Eaton Corp PLC SHS
Stock
$1.5M3.5K
0.9%
+0.8%
Added · +29 sh
38Walmart Inc Com
Stock
$1.5M12.9K
0.9%
−1.5%
Reduced · −203 sh
39Ishares Msci Eafe Value ETF
ETF
$1.4M18.5K
0.9%
−0.1%
Reduced · −19 sh
40Dover Corp Com
Stock
$1.3M5.7K
0.8%
+0.9%
Added · +54 sh
41Legalzoom Com Inc Com
Stock
$1.2M200.0K
0.7%
−11%
Reduced · −25K sh
42Ishares Msci Eafe Growth ETF
ETF
$1.2M9.8K
0.7%
−0.1%
Reduced · −10 sh
43Oreilly Automotive Inc Com
Stock
$1.2M12.6K
0.7%
−0.6%
Reduced · −74 sh
44Ishares U.S. Technology ETF
ETF
$1.1M4.5K
0.7%
−0.5%
Reduced · −21 sh
45Visa Inc Com CL A
Stock
$1.1M3.2K
0.7%
−3.6%
Reduced · −121 sh
46Broadcom Inc Com
Stock
$1.1M2.8K
0.6%
−1.0%
Reduced · −28 sh
47Applied Matls Inc Com
Stock
$1.1M1.5K
0.6%
Held
48Ishares Core Msci Emerging Markets ETF
ETF
$973K11.7K
0.6%
−0.1%
Reduced · −6 sh
49Ishares S&P 500 Growth ETF
ETF
$945K6.9K
0.6%
−0.1%
Reduced · −5 sh
50Chevron Corporation Com
Stock
$847K5.1K
0.5%
Held
Showing 50 of 90 positions
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Filing history

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

$166.1M · Q2 2026Q3 2024 · $117.6MQ2 2026 · $166.1M

Reported 13F total per quarter. Raw filing totals can include option notional.

QuarterAs ofFiledLagPositionsValueForm
Q2 2026Jun 30, 2026Jul 15, 202615d90$166.1M13F-HR
Q1 2026Mar 31, 2026Apr 17, 202617d88$149.1M13F-HR
Q4 2025Dec 31, 2025Jan 21, 202621d88$152.8M13F-HR
Q3 2025Sep 30, 2025Oct 20, 202520d87$150.4M13F-HR
Q2 2025Jun 30, 2025Jul 15, 202515d84$137.5M13F-HR
Q1 2025Mar 31, 2025Apr 28, 202528d86$126.2M13F-HR
Q4 2024Dec 31, 2024Feb 6, 202537d322$142.6M13F-HR
Q3 2024Sep 30, 2024Oct 31, 202431d84$117.6M13F-HR

Data source

Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. Book totals and portfolio weights cover reported non-option positions, which can include notes and warrants. 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.