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 | |
|---|---|---|---|---|---|---|
51
CALL
VanEck Gold Miners ETF
GDX
$22.7B
| $373M | 0.21% |
2,534,800
-2,630,200
| -51% | -$208M |
|
|
52
PUT
Alibaba
BABA
$283B
| $350M | 0.2% |
2,559,200
-434,100
| -15% | -$70.7M |
|
53
CALL
Robinhood
HOOD
$95.5B
| $345M | 0.19% |
3,054,200
-1,300,300
| -30% | -$169M |
|
54
CALL
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
$46B
| $330M | 0.19% |
686,300
+145,300
| +27% | +$68.7M |
|
55
CALL
Berkshire Hathaway Class B
BRK.B
$1.06T
| $322M | 0.18% |
641,300
+9,700
| +2% | +$4.83M |
|
56
CALL
Citigroup
C
$223B
| $311M | 0.18% |
2,667,900
-238,100
| -8% | -$24.7M |
|
57
CALL
Costco
COST
$412B
| $289M | 0.16% |
335,700
+61,000
| +22% | +$55.3M |
|
58
PUT
ASML
ASML
$692B
| $283M | 0.16% |
264,700
-37,500
| -12% | -$39.1M |
|
59
CALL
Boeing
BA
$161B
| $262M | 0.15% |
1,207,700
-320,800
| -21% | -$66M |
|
|
60
PUT
Citigroup
C
$223B
| $262M | 0.15% |
2,242,300
-200,500
| -8% | -$20.8M |
|
61
PUT
Goldman Sachs
GS
$320B
| $261M | 0.15% |
297,200
-25,000
| -8% | -$20.4M |
|
62
CALL
JPMorgan Chase
JPM
$918B
| $258M | 0.15% |
799,900
+42,400
| +6% | +$13.1M |
|
63
CALL
State Street SPDR NYSE Technology ETF
XNTK
$2.16B
| $255M | 0.14% |
2,679,200
-2,634,300
| -50% | -$736M |
|
64
CALL
Pinduoduo
PDD
$121B
| $241M | 0.14% |
2,129,600
+459,700
| +28% | +$57.1M |
|
|
65
PUT
Robinhood
HOOD
$95.5B
| $239M | 0.13% |
2,108,800
-1,257,100
| -37% | -$163M |
|
|
66
PUT
JPMorgan Chase
JPM
$918B
| $236M | 0.13% |
733,600
-413,200
| -36% | -$128M |
|
67
CALL
Applovin
APP
$144B
| $235M | 0.13% |
348,600
-201,000
| -37% | -$127M |
|
68
CALL
Coinbase
COIN
$46.3B
| $233M | 0.13% |
1,029,900
+57,300
| +6% | +$17.1M |
|
69
PUT
Walmart Inc
WMT
$878B
| $229M | 0.13% |
2,056,200
+293,200
| +17% | +$31.5M |
|
70
CALL
PayPal
PYPL
$49.3B
| $222M | 0.13% |
3,804,500
+1,067,300
| +39% | +$69.3M |
|
71
PUT
Cisco
CSCO
$442B
| $219M | 0.12% |
2,837,500
-720,900
| -20% | -$53.5M |
|
72
CALL
Eli Lilly
LLY
$1.05T
| $211M | 0.12% |
196,500
-38,800
| -16% | -$37.1M |
|
73
PUT
Intel
INTC
$530B
| $206M | 0.12% |
5,592,900
-1,884,900
| -25% | -$71.2M |
|
|
74
PUT
Boeing
BA
$161B
| $205M | 0.12% |
944,700
+51,600
| +6% | +$10.6M |
|
|
75
PUT
Applovin
APP
$144B
| $204M | 0.11% |
302,600
-200,700
| -40% | -$126M |
|
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.