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 | |
|---|---|---|---|---|---|---|
851
CALL
Gold Fields
GFI
$28.9B
| $9.97M | 0.01% |
228,300
-49,500
| -18% | -$2.07M |
|
852
PUT
Sable Offshore Corp
SOC
$878M
| $9.95M | 0.01% |
1,103,200
+475,300
| +76% | +$4.49M |
|
853
Bilibili
BILI
$7.32B
| $9.95M | 0.01% |
404,527
-4,064
| -1% | -$109K |
|
854
CALL
General Mills
GIS
$19B
| $9.95M | 0.01% |
213,900
-2,600
| -1% | -$124K |
|
855
CALL
Wayfair
W
$10.9B
| $9.94M | 0.01% |
99,000
-114,400
| -54% | -$11M |
|
856
PUT
Arthur J. Gallagher & Co
AJG
$62.2B
| $9.94M | 0.01% |
38,400
+22,500
| +142% | +$5.96M |
|
|
857
PUT
Gold Fields
GFI
$28.9B
| $9.88M | 0.01% |
226,200
-29,500
| -12% | -$1.23M |
|
|
P
858
PUT
Everpure Inc
P
$24.8B
| $9.87M | 0.01% |
147,300
+22,100
| +18% | +$1.85M |
|
859
CALL
Invesco DB US Dollar Index Bullish Fund
UUP
$434M
| $9.86M | 0.01% |
478,400
-12,600
| -3% | -$352K |
|
860
PUT
AstraZeneca
AZN
$261B
| $9.86M | 0.01% |
53,650
-21,600
| -29% | -$3.79M |
|
861
CALL
AerCap
AER
$23.4B
| $9.83M | 0.01% |
68,400
-2,000
| -3% | -$265K |
|
862
PUT
Sharplink Inc
SBET
$1.26B
| $9.76M | 0.01% |
1,092,100
-498,400
| -31% | -$6.09M |
|
863
CALL
Alamos Gold
AGI
$12.3B
| $9.75M | 0.01% |
252,700
-137,900
| -35% | -$4.8M |
|
864
CALL
3M
MMM
$87.2B
| $9.69M | 0.01% |
66,200
-88,900
| -57% | -$14.5M |
|
865
PUT
BigBear.ai
BBAI
$1.37B
| $9.69M | 0.01% |
1,793,600
+106,300
| +6% | +$694K |
|
866
Rigetti Computing
RGTI
$4.93B
| $9.64M | 0.01% |
435,326
+207,892
| +91% | +$6.78M |
|
867
CALL
Intuitive Machines
LUNR
$2.2B
| $9.62M | 0.01% |
593,000
+32,400
| +6% | +$375K |
|
868
CALL
Lumen
LUMN
$6.66B
| $9.62M | 0.01% |
1,238,300
-1,012,000
| -45% | -$8.33M |
|
869
CALL
BridgeBio Pharma
BBIO
$16.3B
| $9.61M | 0.01% |
125,700
-78,800
| -39% | -$5.17M |
|
870
PUT
D.R. Horton
DHI
$39.8B
| $9.61M | 0.01% |
66,700
-94,900
| -59% | -$14.4M |
|
871
CALL
Brookfield
BN
$101B
| $9.6M | 0.01% |
209,300
+68,450
| +49% | +$3.12M |
|
872
CALL
Electronic Arts
EA
$52.4B
| $9.58M | 0.01% |
46,900
-186,000
| -80% | -$37.5M |
|
873
PUT
AGNC Investment
AGNC
$12.2B
| $9.55M | 0.01% |
890,700
-364,800
| -29% | -$3.75M |
|
874
United Airlines
UAL
$37.4B
| $9.54M | 0.01% |
+85,296
| New | +$8.62M |
|
875
PUT
Sprott Uranium Miners ETF
URNM
$1.84B
| $9.53M | 0.01% |
174,700
+136,700
| +360% | +$7.9M |
|
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.