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 | |
|---|---|---|---|---|---|---|
|
CHYM
4051
PUT
Chime Financial
CHYM
$8.64B
| $237K | ﹤0.01% |
9,400
-11,700
| -55% | -$249K |
|
4052
PUT
Mirion Technologies
MIR
$3.6B
| $237K | ﹤0.01% |
10,100
-156,600
| -94% | -$3.91M |
|
4053
PUT
Group 1 Automotive
GPI
$4.4B
| $236K | ﹤0.01% |
600
-4,900
| -89% | -$2.01M |
|
4054
PUT
Watsco Inc
WSO
$12.9B
| $236K | ﹤0.01% |
+700
| New | +$250K |
|
4055
CALL
CVR Partners
UAN
$1.28B
| $236K | ﹤0.01% |
2,300
-11,600
| -83% | -$1.1M |
|
4056
Corteva
CTVA
$60.7B
| $236K | ﹤0.01% |
3,517
-8,234
| -70% | -$532K |
|
4057
PUT
Alpha and Omega Semiconductor
AOSL
$857M
| $236K | ﹤0.01% |
11,900
+10,700
| +892% | +$253K |
|
4058
PUT
Arteris
AIP
$1.3B
| $236K | ﹤0.01% |
15,200
+15,100
| +15,100% | +$219K |
|
4059
PUT
Genesis Energy
GEL
$1.85B
| $236K | ﹤0.01% |
15,100
-10,200
| -40% | -$160K |
|
4060
CACI
CACI
$10.8B
| $236K | ﹤0.01% |
442
+158
| +56% | +$89.3K |
|
4061
PUT
SouthState Bank Corp
SSB
$10.3B
| $235K | ﹤0.01% |
2,500
-500
| -17% | -$46.3K |
|
4062
PUT
Albertsons Companies
ACI
$5.94B
| $235K | ﹤0.01% |
13,700
+5,600
| +69% | +$99.9K |
|
4063
CALL
Jackson Financial
JXN
$8.52B
| $235K | ﹤0.01% |
2,200
-4,900
| -69% | -$487K |
|
|
TERN
4064
PUT
DELISTED
Terns Pharmaceuticals
TERN
| $234K | ﹤0.01% |
5,800
+3,600
| +164% | +$83.2K |
|
4065
PUT
Peoples Bancorp
PEBO
$1.51B
| $234K | ﹤0.01% |
7,800
-3,100
| -28% | -$92.1K |
|
4066
CALL
Vanguard Total International Stock ETF
VXUS
$153B
| $234K | ﹤0.01% |
3,100
-2,000
| -39% | -$149K |
|
4067
PUT
Intapp
INTA
$2.49B
| $234K | ﹤0.01% |
5,100
+1,900
| +59% | +$78.8K |
|
4068
Commault Systems
CVLT
$5.05B
| $233K | ﹤0.01% |
1,860
-3,983
| -68% | -$560K |
|
4069
PUT
Lazard
LAZ
$4.03B
| $233K | ﹤0.01% |
4,800
+4,700
| +4,700% | +$235K |
|
4070
iShares S&P GSCI Commodity-Indexed Trust
GSG
$1B
| $233K | ﹤0.01% |
10,101
+3,612
| +56% | +$83.2K |
|
|
NAGE
4071
PUT
Niagen Bioscience
NAGE
$256M
| $233K | ﹤0.01% |
36,600
+17,100
| +88% | +$119K |
|
4072
PUT
Liberty Media Series A
FWONA
$23.5B
| $233K | ﹤0.01% |
2,400
-400
| -14% | -$35.9K |
|
4073
BBB Foods
TBBB
$4.78B
| $233K | ﹤0.01% |
6,964
+5,210
| +297% | +$156K |
|
4074
CALL
Northern Trust
NTRS
$22B
| $232K | ﹤0.01% |
1,700
-1,500
| -47% | -$197K |
|
4075
Frontier Group Holdings
ULCC
$1.53B
| $232K | ﹤0.01% |
49,282
+14,110
| +40% | +$62.5K |
|
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.