Simplex Trading Portfolio holdings
Simplex Trading, founded in 2004 and headquartered in Chicago, Illinois, is a technology-driven proprietary trading firm specializing in market-making and liquidity provision, primarily in U.S. equity options and futures options. Leveraging advanced proprietary software and data-driven analysis, the firm optimizes trading strategies and develops innovative solutions to capitalize on financial market opportunities, maintaining a competitive edge through automation and a collaborative team of technologists and traders. With a workforce exceeding 300 and led by CEO Erik Swanson since 2014, Simplex operates with a low-ego, high-intelligence culture, focusing on minimal bureaucracy and rapid execution, while also making strategic venture capital investments in fintech startups. Recognized as a top workplace in Chicago by Built In’s 2025 awards, Simplex continues to evolve, blending cutting-edge technology with a commitment to market efficiency and growth.
Top Buys
| Rank | Stock | Value |
|---|---|---|
| 1 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.59% |
| 2 | Consumer Discretionary | 0.21% |
| 3 | Healthcare | 0.2% |
| 4 | Industrials | 0.18% |
| 5 | Communication Services | 0.16% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
7051
CALL
QuickLogic
QUIK
$211M
| $9.01K | ﹤0.01% |
1,500
-3,000
| -67% | -$19.4K |
|
|
IONX
7052
Defiance Daily Target 2X Long IONQ ETF
IONX
$98M
| $9.01K | ﹤0.01% |
+138
| New | +$17.9K |
|
|
IMDX
7053
CALL
Insight Molecular Diagnostics
IMDX
$141M
| $9K | ﹤0.01% |
+1,200
| New | +$6.77K |
|
|
COII
7054
CALL
DELISTED
REX COIN Covered Call ETF
COII
| $9K | ﹤0.01% |
+600
| New | +$12K |
|
7055
CALL
Dole
DOLE
$1.38B
| $8.99K | ﹤0.01% |
600
-23,500
| -98% | -$327K |
|
7056
CALL
AngioDynamics
ANGO
$605M
| $8.99K | ﹤0.01% |
700
-11,300
| -94% | -$139K |
|
7057
CALL
Assured Guaranty
AGO
$3.73B
| $8.99K | ﹤0.01% |
100
-300
| -75% | -$25.9K |
|
7058
VSE Corp
VSEC
$5.19B
| $8.98K | ﹤0.01% |
52
-665
| -93% | -$114K |
|
7059
CALL
PharmaCyte Biotech
PMCB
$6.29M
| $8.98K | ﹤0.01% |
+12,400
| New | +$11.2K |
|
|
UCYB
7060
ProShares Ultra Nasdaq Cybersecurity ETF
UCYB
$6.63M
| $8.94K | ﹤0.01% |
170
-230
| -58% | -$13.5K |
|
7061
PUT
Delek Logistics
DKL
$3.12B
| $8.92K | ﹤0.01% |
200
-1,100
| -85% | -$49.4K |
|
7062
Valens Semiconductor
VLN
$160M
| $8.92K | ﹤0.01% |
6,282
-19,479
| -76% | -$32.1K |
|
7063
PUT
Bankunited
BKU
$3.33B
| $8.91K | ﹤0.01% |
200
-200
| -50% | -$8.28K |
|
7064
CALL
SPS Commerce
SPSC
$2.55B
| $8.91K | ﹤0.01% |
100
| – | – |
|
7065
Mission Produce
AVO
$1.14B
| $8.88K | ﹤0.01% |
766
-1,400
| -65% | -$16.8K |
|
7066
PUT
Inovio Pharmaceuticals
INO
$85.6M
| $8.87K | ﹤0.01% |
5,100
+800
| +19% | +$1.76K |
|
7067
CALL
Treace Medical Concepts
TMCI
$262M
| $8.82K | ﹤0.01% |
3,600
-100
| -3% | -$434 |
|
|
UDMY
7068
PUT
DELISTED
Udemy
UDMY
| $8.78K | ﹤0.01% |
1,500
+1,300
| +650% | +$7.58K |
|
7069
CALL
Trevi Therapeutics
TRVI
$2.57B
| $8.76K | ﹤0.01% |
700
-105,000
| -99% | -$1.21M |
|
7070
PUT
IZEA Worldwide
IZEA
$58.7M
| $8.76K | ﹤0.01% |
+2,000
| New | +$9.72K |
|
7071
ProShares Short Real Estate
REK
$11.5M
| $8.76K | ﹤0.01% |
509
+292
| +135% | +$4.98K |
|
|
FPI
7072
PUT
Farmland Partners
FPI
$415M
| $8.72K | ﹤0.01% |
900
-1,100
| -55% | -$11K |
|
7073
PUT
Invesco Galaxy Bitcoin ETF
BTCO
$426M
| $8.72K | ﹤0.01% |
+100
| New | +$9.98K |
|
7074
PUT
Tenaya Therapeutics
TNYA
$160M
| $8.69K | ﹤0.01% |
12,200
-3,100
| -20% | -$4.22K |
|
|
EU
7075
PUT
enCore Energy
EU
$206M
| $8.68K | ﹤0.01% |
3,500
-26,400
| -88% | -$75.5K |
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading withdrew a net $23.2B in Q4 2025, closing 2,184 positions and reducing 4,088 holdings. Its most notable exit was iShares Russell 2000 ETF, an estimated $149M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.59% of assets, down from 0.79% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Western Digital worth $58.9M.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.