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 | |
|---|---|---|---|---|---|---|
1201
PUT
Enbridge
ENB
$124B
| $5.58M | ﹤0.01% |
116,600
+24,000
| +26% | +$1.15M |
|
1202
EQT Corp
EQT
$33.4B
| $5.55M | ﹤0.01% |
103,612
+22,190
| +27% | +$1.25M |
|
1203
Atlassian
TEAM
$21.6B
| $5.54M | ﹤0.01% |
34,148
+6,214
| +22% | +$975K |
|
1204
CALL
Denison Mines
DNN
$2.7B
| $5.53M | ﹤0.01% |
2,080,700
+936,200
| +82% | +$2.55M |
|
1205
CALL
Cheniere Energy
LNG
$56.6B
| $5.5M | ﹤0.01% |
28,300
-46,100
| -62% | -$9.68M |
|
1206
PUT
MPLX
MPLX
$59.3B
| $5.49M | ﹤0.01% |
102,800
-11,500
| -10% | -$600K |
|
1207
CALL
Tencent Music
TME
$14.5B
| $5.46M | ﹤0.01% |
311,200
+82,500
| +36% | +$1.67M |
|
1208
CALL
Alignment Healthcare
ALHC
$4.15B
| $5.45M | ﹤0.01% |
275,700
+10,600
| +4% | +$190K |
|
1209
Biogen
BIIB
$30B
| $5.43M | ﹤0.01% |
30,878
+29,762
| +2,667% | +$4.86M |
|
1210
CALL
Conagra Brands
CAG
$7.05B
| $5.43M | ﹤0.01% |
313,700
+53,600
| +21% | +$952K |
|
1211
Alcoa
AA
$11.9B
| $5.43M | ﹤0.01% |
102,172
-75,177
| -42% | -$3.08M |
|
1212
PUT
Campbell Soup
CPB
$6.47B
| $5.4M | ﹤0.01% |
193,900
-56,600
| -23% | -$1.7M |
|
1213
PUT
Fluence Energy
FLNC
$1.85B
| $5.4M | ﹤0.01% |
272,900
+51,100
| +23% | +$963K |
|
1214
CALL
Darden Restaurants
DRI
$22.5B
| $5.39M | ﹤0.01% |
29,300
-1,800
| -6% | -$328K |
|
1215
Chevron
CVX
$387B
| $5.39M | ﹤0.01% |
35,375
+9,699
| +38% | +$1.48M |
|
1216
PUT
Steel Dynamics
STLD
$35.4B
| $5.39M | ﹤0.01% |
31,800
-6,600
| -17% | -$1.05M |
|
1217
PUT
Proshares UltraShort Technology
REW
$3.46M
| $5.38M | ﹤0.01% |
125,300
-298,975
| -70% | -$6.69M |
|
1218
Texas Instruments
TXN
$256B
| $5.37M | ﹤0.01% |
+30,972
| New | +$5.3M |
|
1219
CALL
FuelCell Energy
FCEL
$1.78B
| $5.37M | ﹤0.01% |
734,700
+170,100
| +30% | +$1.39M |
|
1220
CALL
Macy's
M
$6.16B
| $5.35M | ﹤0.01% |
242,700
-19,300
| -7% | -$395K |
|
1221
CALL
Mondelez International
MDLZ
$77.4B
| $5.34M | ﹤0.01% |
99,200
-36,400
| -27% | -$2.1M |
|
|
OKLO
1222
Oklo
OKLO
$7.2B
| $5.33M | ﹤0.01% |
74,304
-95,292
| -56% | -$10.6M |
|
1223
PUT
Transocean
RIG
$5.91B
| $5.29M | ﹤0.01% |
1,280,200
-67,500
| -5% | -$262K |
|
1224
CALL
FuboTV Inc
FUBO
$252M
| $5.28M | ﹤0.01% |
174,483
+21,558
| +14% | +$860K |
|
|
PR
1225
CALL
Permian Resources
PR
$17.9B
| $5.27M | ﹤0.01% |
375,800
-42,700
| -10% | -$573K |
|
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.