SIMPLEX TRADING, LLC

Market maker Mechanical CIK 1488542
League rank
#11
in Market maker · #976 overall
Long book
$3.23B
Q1 2026
Positions
2613
Top-10 weight
37%
concentration
Last quarter
+17.1%
SPY +14.8%
Turnover
58%
of book per quarter

Strategy in plain words

auto-generated from filings

SIMPLEX TRADING, LLC is a market maker — positions are inventory, not bets, running a $3.23B US long book across 2613 positions.

The portfolio is moderately concentrated (top 10 ≈ 37% of the book). Turnover is high — positions rotate quickly, so individual names matter less than the process. Current anchor positions: NVIDIA CORP, AMAZON.COM INC, SS SPDR S&P 500 ETF TRUST-US, META PLATFORMS INC-CLASS A, TAIWAN SEMICONDUCTOR-SP ADR.

Over the last 9 quarters its long book ran on average 1pp per quarter ahead of the S&P 500, beating the index in 5 of 9 quarters. Its holdings are mechanical (indexing / client flows), so position changes carry no stock-picking signal.

Implied long-book return vs S&P 500

methodology: positions priced quarterly, no shorts/options
Fund long book S&P 500
Q1 2024
-0.9%
Q2 2024
+5.4%
Q3 2024
-0.8%
Q4 2024
-3.6%
Q1 2025
+14.9%
Q2 2025
+17.6%
Q3 2025
+0.7%
Q4 2025
-0.9%
Q1 2026
+17.1%

Sector allocation

Technology
45%
Financials
10%
Consumer discretionary
9%
Industrials
9%
Healthcare
7%
Materials
5%
Other
4%
Energy
3%

Long book by quarter

$3.43B
Q1 2024
$3.11B
Q2 2024
$2.97B
Q3 2024
$3.55B
Q4 2024
$2.82B
Q1 2025
$3.72B
Q2 2025
$4.53B
Q3 2025
$3.56B
Q4 2025
$3.23B
Q1 2026

What does SIMPLEX TRADING, own?

Q1 2026 13F
CompanySectorSharesValue% of bookChange
NVDA NVIDIA CORPTechnology1.5M$263.2M8.1%+103.7%
AMZN AMAZON.COM INCConsumer discretionary764.9K$159.3M4.9%New
META META PLATFORMS INC-CLASS ATechnology229.9K$131.5M4.1%+266.8%
GOOGL ALPHABET INC-CL ATechnology296.3K$85.2M2.6%+664.3%
UNH UNITEDHEALTH GROUP INCFinancials287.6K$77.8M2.4%+210.1%
ORCL ORACLE CORPTechnology514.7K$75.7M2.3%+291.7%
AMD ADVANCED MICRO DEVICESTechnology260.6K$53.0M1.6%+361.5%
MSFT MICROSOFT CORPTechnology136.7K$50.6M1.6%+93.6%
GOOG ALPHABET INC-CL CTechnology145.4K$41.7M1.3%+199.7%
LITE LUMENTUM HOLDINGS INCTechnology52.8K$37.1M1.1%+198.0%
PFE PFIZER INCHealthcare1.3M$35.6M1.1%-15.0%
PLTR PALANTIR TECHNOLOGIES INC-ATechnology231.3K$33.8M1.0%+20.9%
INTC INTEL CORPTechnology757.7K$33.4M1.0%-30.0%
SLB SLB LTDEnergy547.1K$28.1M0.9%+14.2%
CI THE CIGNA GROUPFinancials98.2K$26.2M0.8%-29.9%
ASML ASML HOLDING NV-NY REG SHSIndustrials16.7K$22.1M0.7%New
NKE NIKE INC -CL BOther398.2K$21.0M0.7%+42.6%
DOW DOW INCMaterials459.3K$19.0M0.6%+54.5%
PEP PEPSICO INCConsumer staples121.6K$18.9M0.6%New
NFLX NETFLIX INCServices media184.9K$17.8M0.6%-73.2%
SOFI SOFI TECHNOLOGIES INCFinancials968.4K$15.4M0.5%-46.4%
GEV GE VERNOVA INCIndustrials16.9K$14.8M0.5%+57.8%
FCX FREEPORT-MCMORAN INCMaterials244.8K$14.4M0.4%-56.8%
BKNG BOOKING HOLDINGS INCIndustrials3.3K$14.1M0.4%-35.1%
CHTR CHARTER COMMUNICATIONS INC-ACommunications62.6K$13.5M0.4%New
AVGO BROADCOM INCTechnology43.2K$13.4M0.4%-81.4%
UNP UNION PACIFIC CORPIndustrials54.0K$13.1M0.4%+2483.9%
B BARRICK MINING CORPMaterials297.9K$12.2M0.4%+16.3%
MS MORGAN STANLEYFinancials73.1K$12.0M0.4%+8.7%
MRNA MODERNA INCHealthcare219.6K$11.2M0.3%+144.9%
NOW SERVICENOW INCTechnology96.6K$10.1M0.3%+123.8%
AAPL APPLE INCTechnology39.8K$10.1M0.3%-94.4%
ALAB ASTERA LABS INCTechnology91.9K$10.1M0.3%New
AXTI AXT INCTechnology173.6K$9.9M0.3%+97.9%
ESLT ELBIT SYSTEMS LTDIndustrials11.0K$9.4M0.3%+1246.6%
ZTS ZOETIS INCHealthcare74.7K$8.8M0.3%+8.9%
SNAP SNAP INC - ATechnology1.7M$7.9M0.2%+12.8%
ET ENERGY TRANSFER LPUtilities394.2K$7.6M0.2%-46.2%
TSLA TESLA INCIndustrials20.2K$7.5M0.2%-83.2%
CP CANADIAN PACIFIC KANSAS CITYIndustrials92.0K$7.2M0.2%New
IREN IREN LTDFinancials207.8K$7.1M0.2%+8.3%
ADI ANALOG DEVICES INCTechnology22.0K$7.0M0.2%+568.0%
CAMT CAMTEK LTDOther43.2K$6.6M0.2%New
APGE APOGEE THERAPEUTICS INCHealthcare77.8K$6.5M0.2%+23.9%
DAL DELTA AIR LINES INCIndustrials98.3K$6.5M0.2%New
OSCR OSCAR HEALTH INC - CLASS AFinancials565.2K$6.5M0.2%-11.6%
GLW CORNING INCIndustrials47.4K$6.4M0.2%+45.4%
CCJ CAMECO CORPMaterials55.9K$6.1M0.2%+16.1%
OKTA OKTA INCTechnology76.8K$6.0M0.2%+162.6%
PEN PENUMBRA INCHealthcare17.7K$5.8M0.2%+13530.0%

13F filing history

PeriodFormFiledEntriesReported valueFlagsSource
Q1 202613F-HRMay 14, 202610161$149.08B canonicalSEC ↗
Q4 202513F-HRFeb 11, 20269381$177.42B canonicalSEC ↗
Q3 202513F-HRNov 12, 202510359$194.89B $K fixed canonicalSEC ↗
Q2 202513F-HRAug 5, 20259904$174.65B $K fixed canonicalSEC ↗
Q1 202513F-HRMay 12, 20259739$156.19B $K fixed canonicalSEC ↗
Q4 202413F-HRFeb 11, 20259701$178.63B $K fixed canonicalSEC ↗
Q3 202413F-HRNov 8, 20249647$170.39B $K fixed canonicalSEC ↗
Q2 202413F-HRJul 25, 20249955$161.88B $K fixed canonicalSEC ↗
Q1 202413F-HRApr 25, 202410037$173.12B $K fixed canonicalSEC ↗