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 | |
|---|---|---|---|---|---|---|
126
PUT
Arm
ARM
$309B
| $122M | 0.07% |
1,115,800
-202,700
| -15% | -$29.5M |
|
127
PUT
Pinduoduo
PDD
$121B
| $121M | 0.07% |
1,067,000
-1,067,700
| -50% | -$133M |
|
128
PUT
Applied Materials
AMAT
$448B
| $121M | 0.07% |
470,400
-3,800
| -0.8% | -$911K |
|
129
CALL
Walt Disney
DIS
$167B
| $120M | 0.07% |
1,052,000
-414,300
| -28% | -$45.6M |
|
130
CALL
Palo Alto Networks
PANW
$279B
| $117M | 0.07% |
635,500
-211,500
| -25% | -$42.7M |
|
131
CALL
Vanguard S&P 500 ETF
VOO
$981B
| $117M | 0.07% |
229,600
-8,500
| -4% | -$5.28M |
|
132
CALL
First Solar
FSLR
$22.1B
| $117M | 0.07% |
446,500
+18,900
| +4% | +$4.77M |
|
|
133
CALL
Applied Materials
AMAT
$448B
| $116M | 0.07% |
451,500
+18,700
| +4% | +$4.48M |
|
134
PUT
Morgan Stanley
MS
$340B
| $115M | 0.07% |
649,600
-326,300
| -33% | -$54.4M |
|
|
135
PUT
Palo Alto Networks
PANW
$279B
| $115M | 0.07% |
626,000
+9,400
| +2% | +$1.9M |
|
136
PUT
Marvell Technology
MRVL
$187B
| $115M | 0.07% |
1,356,000
-436,600
| -24% | -$38.2M |
|
137
CALL
lululemon athletica
LULU
$13.2B
| $115M | 0.06% |
553,400
-289,300
| -34% | -$52.4M |
|
138
CALL
Bank of America
BAC
$430B
| $115M | 0.06% |
2,090,100
-1,514,800
| -42% | -$80.1M |
|
139
PUT
Iris Energy
IREN
$14.8B
| $115M | 0.06% |
3,038,300
-1,578,700
| -34% | -$81.4M |
|
140
PUT
Dell
DELL
$261B
| $113M | 0.06% |
899,100
-16,500
| -2% | -$2.32M |
|
141
PUT
Freeport-McMoran
FCX
$89.9B
| $113M | 0.06% |
2,221,500
-363,400
| -14% | -$15.7M |
|
|
ETHA
142
CALL
iShares Ethereum Trust ETF
ETHA
$5.43B
| $111M | 0.06% |
4,961,700
-353,400
| -7% | -$9.24M |
|
143
PUT
Qualcomm
QCOM
$183B
| $111M | 0.06% |
646,800
-53,300
| -8% | -$9.14M |
|
144
CALL
Newmont
NEM
$98.7B
| $106M | 0.06% |
1,062,900
-417,900
| -28% | -$37.8M |
|
|
145
PUT
lululemon athletica
LULU
$13.2B
| $106M | 0.06% |
510,300
-278,800
| -35% | -$50.5M |
|
|
146
CALL
Arm
ARM
$309B
| $106M | 0.06% |
968,800
-272,800
| -22% | -$39.7M |
|
147
PUT
Johnson & Johnson
JNJ
$599B
| $105M | 0.06% |
508,800
-10,000
| -2% | -$1.98M |
|
148
CALL
Shopify
SHOP
$160B
| $105M | 0.06% |
652,200
-81,300
| -11% | -$13.1M |
|
149
CALL
Super Micro Computer
SMCI
$16.5B
| $105M | 0.06% |
3,582,900
+142,600
| +4% | +$5.87M |
|
150
PUT
Adobe
ADBE
$90.3B
| $105M | 0.06% |
299,200
-62,300
| -17% | -$21.2M |
|
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.