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 | |
|---|---|---|---|---|---|---|
|
HTO
5876
CALL
H2O America
HTO
$2.57B
| $39.2K | ﹤0.01% |
800
+500
| +167% | +$24K |
|
|
HTO
5877
PUT
H2O America
HTO
$2.57B
| $39.2K | ﹤0.01% |
800
-300
| -27% | -$14.4K |
|
|
AIFC
5878
PUT
AI Financial Corp
AIFC
$57.6M
| $39K | ﹤0.01% |
35,500
-39,900
| -53% | -$76.8K |
|
5879
CALL
Safety Insurance
SAFT
$1.52B
| $39K | ﹤0.01% |
500
+200
| +67% | +$14.8K |
|
5880
CALL
iRadimed
IRMD
$1.16B
| $38.9K | ﹤0.01% |
400
+300
| +300% | +$25.7K |
|
5881
Thomson Reuters
TRI
$42.8B
| $38.9K | ﹤0.01% |
+290
| New | +$42K |
|
5882
CALL
TIM SA
TIMB
$9.16B
| $38.9K | ﹤0.01% |
+2,000
| New | +$43.9K |
|
|
VPU
5883
Vanguard Utilities ETF
VPU
$8.46B
| $38.9K | ﹤0.01% |
+210
| New | +$40.3K |
|
5884
CALL
Ezcorp Inc
EZPW
$1.83B
| $38.8K | ﹤0.01% |
2,000
-45,200
| -96% | -$852K |
|
|
TGNA
5885
CALL
DELISTED
TEGNA Inc
TGNA
| $38.8K | ﹤0.01% |
2,000
-1,600
| -44% | -$31.6K |
|
|
LB
5886
LandBridge Co
LB
$2.16B
| $38.8K | ﹤0.01% |
791
-411
| -34% | -$23.9K |
|
5887
PUT
Lifestance Health
LFST
$4B
| $38.7K | ﹤0.01% |
5,500
-600
| -10% | -$3.62K |
|
5888
PUT
SBA Communications
SBAC
$19.2B
| $38.7K | ﹤0.01% |
200
-16,800
| -99% | -$3.25M |
|
5889
PUT
Atlas Energy Solutions
AESI
$1.35B
| $38.6K | ﹤0.01% |
4,100
-11,400
| -74% | -$115K |
|
5890
AmpliTech
AMPG
$118M
| $38.6K | ﹤0.01% |
+12,911
| New | +$43.6K |
|
5891
TransUnion
TRU
$15.1B
| $38.6K | ﹤0.01% |
450
-2,145
| -83% | -$176K |
|
5892
CALL
Driven Brands
DRVN
$2.35B
| $38.5K | ﹤0.01% |
2,600
-7,700
| -75% | -$115K |
|
|
AFCG
5893
CALL
AFC Gamma
AFCG
$61.4M
| $38.5K | ﹤0.01% |
13,500
-1,100
| -8% | -$3.49K |
|
5894
PUT
Innoviz Technologies
INVZ
$95M
| $38.3K | ﹤0.01% |
44,900
-253,100
| -85% | -$401K |
|
5895
CALL
National Health Investors
NHI
$3.72B
| $38.2K | ﹤0.01% |
500
-500
| -50% | -$38.3K |
|
5896
Waterstone Financial
WSBF
$370M
| $38.2K | ﹤0.01% |
2,306
+944
| +69% | +$14.8K |
|
|
LITS
5897
CALL
Lite Strategy Inc
LITS
$32.8M
| $38.1K | ﹤0.01% |
28,900
-35,800
| -55% | -$67.6K |
|
5898
PUT
Richardson Electronics
RELL
$267M
| $38.1K | ﹤0.01% |
+3,500
| New | +$37.3K |
|
|
HI
5899
CALL
DELISTED
Hillenbrand
HI
| $38.1K | ﹤0.01% |
+1,200
| New | +$37K |
|
5900
ZipRecruiter
ZIP
$321M
| $38K | ﹤0.01% |
9,749
-11,425
| -54% | -$51.4K |
|
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.