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 | |
|---|---|---|---|---|---|---|
101
CALL
JD.com
JD
$41.1B
| $144M | 0.08% |
5,032,400
+45,700
| +0.9% | +$1.43M |
|
|
UWC
102
PUT
DELISTED
PROSHARES TR ULTRA RUSSELL3000
UWC
| $143M | 0.08% |
2,201,400
+505,700
| +30% | +$32.8M |
|
103
CALL
Visa
V
$677B
| $140M | 0.08% |
398,300
+20,700
| +5% | +$7.05M |
|
104
CALL
Johnson & Johnson
JNJ
$603B
| $139M | 0.08% |
673,900
+208,800
| +45% | +$41.3M |
|
105
PUT
Uber
UBER
$146B
| $139M | 0.08% |
1,699,600
-71,900
| -4% | -$6.47M |
|
|
106
NVIDIA
NVDA
$5.02T
| $138M | 0.08% |
740,771
-1,408,323
| -66% | -$262M |
|
107
CALL
Reddit
RDDT
$35.8B
| $137M | 0.08% |
596,300
-107,400
| -15% | -$22.6M |
|
108
CALL
SoFi Technologies
SOFI
$22.6B
| $136M | 0.08% |
5,210,000
-945,400
| -15% | -$26.3M |
|
109
CALL
iShares MSCI Australia ETF
EWA
$1.34B
| $136M | 0.08% |
3,841,700
-687,500
| -15% | -$18.2M |
|
|
110
PUT
SoFi Technologies
SOFI
$22.6B
| $136M | 0.08% |
5,177,800
-814,200
| -14% | -$22.7M |
|
111
PUT
ProShares UltraPro Short QQQ
SQQQ
$1.99B
| $135M | 0.08% |
+2,174,900
| New | +$154M |
|
112
PUT
Snowflake
SNOW
$94.2B
| $134M | 0.08% |
613,000
+254,600
| +71% | +$62.1M |
|
|
UWC
113
CALL
DELISTED
PROSHARES TR ULTRA RUSSELL3000
UWC
| $133M | 0.07% |
2,348,500
+34,600
| +1% | +$1.96M |
|
|
CRWV
114
CALL
CoreWeave
CRWV
$43.4B
| $133M | 0.07% |
1,853,200
-124,200
| -6% | -$12.6M |
|
|
115
CALL
Uber
UBER
$146B
| $132M | 0.07% |
1,610,800
-337,400
| -17% | -$30.4M |
|
116
PUT
Nike
NKE
$63.7B
| $130M | 0.07% |
2,033,900
-587,300
| -22% | -$38.3M |
|
117
CALL
Adobe
ADBE
$90.3B
| $128M | 0.07% |
367,000
-127,200
| -26% | -$43.3M |
|
118
PUT
Lam Research
LRCX
$403B
| $126M | 0.07% |
738,600
+153,100
| +26% | +$23.8M |
|
119
PUT
AST SpaceMobile
ASTS
$18.9B
| $126M | 0.07% |
1,738,800
+210,000
| +14% | +$15M |
|
|
NVO
120
CALL
Novo Nordisk
NVO
$218B
| $125M | 0.07% |
2,461,700
-214,800
| -8% | -$11M |
|
121
CALL
Cisco
CSCO
$442B
| $125M | 0.07% |
1,619,800
-927,000
| -36% | -$68.8M |
|
|
122
CALL
Snowflake
SNOW
$94.2B
| $125M | 0.07% |
568,700
+39,200
| +7% | +$9.57M |
|
123
CALL
ExxonMobil
XOM
$629B
| $124M | 0.07% |
1,033,700
-491,300
| -32% | -$57M |
|
124
PUT
Costco
COST
$412B
| $124M | 0.07% |
143,400
-54,300
| -27% | -$49.2M |
|
125
PUT
Vertiv
VRT
$117B
| $123M | 0.07% |
761,400
+140,700
| +23% | +$24.4M |
|
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.