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 | |
|---|---|---|---|---|---|---|
|
VRE
6926
DELISTED
Veris Residential
VRE
| $11K | ﹤0.01% |
+739
| New | +$10.9K |
|
|
NFBK
6927
DELISTED
Northfield Bancorp
NFBK
| $11K | ﹤0.01% |
+962
| New | +$10.7K |
|
6928
PUT
Domo
DOMO
$174M
| $11K | ﹤0.01% |
1,300
-28,800
| -96% | -$339K |
|
6929
Woodside Energy
WDS
$44.4B
| $10.9K | ﹤0.01% |
+700
| New | +$11.1K |
|
6930
CALL
Gaia
GAIA
$46.8M
| $10.9K | ﹤0.01% |
3,000
| – | – |
|
6931
PUT
Key Tronic
KTCC
$43.4M
| $10.9K | ﹤0.01% |
+3,900
| New | +$11.4K |
|
6932
CALL
Standard BioTools
LAB
$351M
| $10.9K | ﹤0.01% |
8,500
-9,400
| -53% | -$12.6K |
|
6933
Fidelity MSCI Utilities Index ETF
FUTY
$2.33B
| $10.9K | ﹤0.01% |
197
-2,896
| -94% | -$166K |
|
6934
Lifecore Biomedical
LFCR
$164M
| $10.9K | ﹤0.01% |
1,328
-2,069
| -61% | -$15.3K |
|
|
BKV
6935
CALL
BKV Corp
BKV
$2.63B
| $10.9K | ﹤0.01% |
+400
| New | +$10K |
|
6936
CALL
OneWater Marine
ONEW
$206M
| $10.8K | ﹤0.01% |
+1,000
| New | +$13.3K |
|
6937
PUT
Hayward Holdings
HAYW
$3.26B
| $10.8K | ﹤0.01% |
700
-5,600
| -89% | -$88.5K |
|
6938
PUT
EverQuote
EVER
$886M
| $10.8K | ﹤0.01% |
400
-7,900
| -95% | -$191K |
|
6939
PUT
Rush Enterprises Class A
RUSHA
$6.21B
| $10.8K | ﹤0.01% |
+200
| New | +$10.4K |
|
6940
SelectQuote
SLQT
$128M
| $10.7K | ﹤0.01% |
7,617
-10,779
| -59% | -$18K |
|
|
PNNT
6941
PUT
Pennant Park Investment Corp
PNNT
$217M
| $10.7K | ﹤0.01% |
1,800
-400
| -18% | -$2.5K |
|
6942
PUT
Fathom Holdings
FTHM
$26.3M
| $10.7K | ﹤0.01% |
10,600
-11,100
| -51% | -$15K |
|
6943
CALL
Buckle
BKE
$2.27B
| $10.7K | ﹤0.01% |
200
-1,000
| -83% | -$55.7K |
|
6944
CALL
Terex
TEX
$7.11B
| $10.7K | ﹤0.01% |
200
-1,000
| -83% | -$50.5K |
|
|
INGM
6945
CALL
Ingram Micro Holding
INGM
$7.01B
| $10.7K | ﹤0.01% |
+500
| New | +$10.8K |
|
6946
PUT
Encompass Health
EHC
$11B
| $10.6K | ﹤0.01% |
100
-3,100
| -97% | -$359K |
|
6947
CALL
IT Tech Packaging
ITP
$2.82M
| $10.6K | ﹤0.01% |
48,500
+7,800
| +19% | +$1.93K |
|
|
MCW
6948
PUT
DELISTED
Mister Car Wash
MCW
| $10.6K | ﹤0.01% |
+1,900
| New | +$10K |
|
|
WPRT
6949
Westport Fuel Systems
WPRT
$32.7M
| $10.5K | ﹤0.01% |
6,705
+5,793
| +635% | +$10.8K |
|
6950
ALPS O'Shares Global Internet Giants ETF
OGIG
$103M
| $10.5K | ﹤0.01% |
+200
| New | +$11K |
|
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.