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 | |
|---|---|---|---|---|---|---|
7001
PUT
Liberty Broadband Class C
LBRDK
$4.79B
| $9.72K | ﹤0.01% |
+200
| New | +$10.4K |
|
|
YALA
7002
CALL
Yalla Group
YALA
$817M
| $9.72K | ﹤0.01% |
1,400
-2,100
| -60% | -$15K |
|
|
ARDT
7003
PUT
Ardent Health
ARDT
$1.54B
| $9.71K | ﹤0.01% |
+1,100
| New | +$12.7K |
|
|
STKL
7004
DELISTED
SunOpta
STKL
| $9.71K | ﹤0.01% |
2,556
-2,632
| -51% | -$11.9K |
|
|
SEG
7005
Seaport Entertainment Group
SEG
$337M
| $9.67K | ﹤0.01% |
+489
| New | +$11K |
|
7006
Schwab U.S Small- Cap ETF
SCHA
$22.3B
| $9.65K | ﹤0.01% |
339
-181
| -35% | -$5.11K |
|
7007
CALL
Atea Pharmaceuticals
AVIR
$379M
| $9.64K | ﹤0.01% |
2,700
+400
| +17% | +$1.27K |
|
7008
PUT
iShares Core Dividend ETF
DIVB
$1.68B
| $9.64K | ﹤0.01% |
200
+100
| +100% | +$5.25K |
|
|
LNAI
7009
Lunai Bioworks
LNAI
$9.16M
| $9.63K | ﹤0.01% |
+1,365
| New | +$12.2K |
|
7010
PUT
ACV Auctions
ACVA
$1.4B
| $9.62K | ﹤0.01% |
1,200
-900
| -43% | -$7.28K |
|
7011
CALL
Franklin International Core Dividend Tilt Index ETF
DIVI
$2.72B
| $9.62K | ﹤0.01% |
300
+200
| +200% | +$7.63K |
|
7012
CALL
Mercantile Bank Corp
MBWM
$1.03B
| $9.62K | ﹤0.01% |
200
| – | – |
|
7013
Digimarc Corp
DMRC
$146M
| $9.6K | ﹤0.01% |
1,463
-3,530
| -71% | -$29.9K |
|
7014
CALL
National Beverage
FIZZ
$3B
| $9.57K | ﹤0.01% |
300
-2,300
| -88% | -$79.1K |
|
|
OLP
7015
One Liberty Properties
OLP
$532M
| $9.54K | ﹤0.01% |
470
+433
| +1,170% | +$8.95K |
|
7016
VanEck Intermediate Muni ETF
ITM
$2.14B
| $9.53K | ﹤0.01% |
+202
| New | +$9.49K |
|
7017
PUT
StoneX
SNEX
$9.39B
| $9.51K | ﹤0.01% |
+225
| New | +$9.43K |
|
7018
CALL
Insteel Industries
IIIN
$593M
| $9.5K | ﹤0.01% |
300
+100
| +50% | +$3.26K |
|
7019
Tidal Trust II Defiance Nasdaq 100 Weekly Distribution ETF
QQQY
$180M
| $9.49K | ﹤0.01% |
+403
| New | +$9.9K |
|
7020
AMERISAFE
AMSF
$549M
| $9.49K | ﹤0.01% |
247
-374
| -60% | -$15.1K |
|
7021
ADC Therapeutics
ADCT
$141M
| $9.48K | ﹤0.01% |
2,687
-5,456
| -67% | -$22.1K |
|
7022
PUT
Coca-Cola Femsa
KOF
$22.9B
| $9.47K | ﹤0.01% |
100
-200
| -67% | -$17.7K |
|
|
SOGP
7023
Sound Group
SOGP
$49.9M
| $9.46K | ﹤0.01% |
814
-9,238
| -92% | -$130K |
|
7024
CALL
Brilliant Earth
BRLT
$18M
| $9.45K | ﹤0.01% |
5,400
-2,200
| -29% | -$4.68K |
|
7025
CALL
CareDx
CDNA
$1.97B
| $9.42K | ﹤0.01% |
500
-3,000
| -86% | -$50.3K |
|
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.