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 | |
|---|---|---|---|---|---|---|
1101
PUT
PureCycle Technologies
PCT
$1.21B
| $6.57M | ﹤0.01% |
764,900
+198,300
| +35% | +$2.11M |
|
1102
CALL
SGHC Ltd
SGHC
$7.36B
| $6.56M | ﹤0.01% |
549,200
+406,200
| +284% | +$4.88M |
|
1103
CALL
Calumet Specialty Products
CLMT
$3.73B
| $6.54M | ﹤0.01% |
328,900
+63,800
| +24% | +$1.23M |
|
1104
PUT
Ionis Pharmaceuticals
IONS
$9.23B
| $6.53M | ﹤0.01% |
82,600
+7,100
| +9% | +$535K |
|
1105
Lumentum
LITE
$64.9B
| $6.53M | ﹤0.01% |
17,722
+11,052
| +166% | +$2.84M |
|
|
CMA
1106
PUT
DELISTED
Comerica
CMA
| $6.52M | ﹤0.01% |
75,000
-7,500
| -9% | -$604K |
|
1107
CALL
SolarEdge
SEDG
$2.75B
| $6.51M | ﹤0.01% |
225,500
-39,500
| -15% | -$1.38M |
|
1108
CALL
Navitas Semiconductor
NVTS
$2.93B
| $6.5M | ﹤0.01% |
910,500
+110,100
| +14% | +$1.06M |
|
1109
CALL
Cintas
CTAS
$81.3B
| $6.49M | ﹤0.01% |
34,500
-18,500
| -35% | -$3.48M |
|
1110
CALL
CoStar Group
CSGP
$11.1B
| $6.48M | ﹤0.01% |
177,600
+3,800
| +2% | +$269K |
|
1111
PUT
Polestar Automotive Holding UK
PSNY
$2.18B
| $6.47M | ﹤0.01% |
302,900
+291,363
| +2,525% | +$6.08M |
|
1112
CALL
Novartis
NVS
$297B
| $6.47M | ﹤0.01% |
46,900
-12,600
| -21% | -$1.65M |
|
1113
PUT
Deutsche Bank
DB
$65.3B
| $6.46M | ﹤0.01% |
167,600
-26,700
| -14% | -$963K |
|
|
1114
Novartis
NVS
$297B
| $6.46M | ﹤0.01% |
46,821
+10
| +0% | +$1.31K |
|
1115
PUT
MGM Resorts International
MGM
$11.5B
| $6.45M | ﹤0.01% |
176,800
-12,800
| -7% | -$434K |
|
1116
CALL
Veeva Systems
VEEV
$29.2B
| $6.45M | ﹤0.01% |
28,900
-8,000
| -22% | -$2.12M |
|
1117
PUT
Noble Corp
NE
$6.88B
| $6.45M | ﹤0.01% |
228,400
-37,700
| -14% | -$1.11M |
|
1118
Structure Therapeutics
GPCR
$3.61B
| $6.45M | ﹤0.01% |
92,668
+67,507
| +268% | +$2.76M |
|
1119
CALL
Sprott Uranium Miners ETF
URNM
$1.84B
| $6.42M | ﹤0.01% |
118,900
-139,100
| -54% | -$8.04M |
|
1120
CALL
NetApp
NTAP
$32.3B
| $6.41M | ﹤0.01% |
59,900
+4,500
| +8% | +$514K |
|
1121
CALL
Sibanye-Stillwater
SBSW
$5.97B
| $6.39M | ﹤0.01% |
448,400
-292,800
| -40% | -$3.54M |
|
|
LAC
1122
CALL
Lithium Americas
LAC
$1.02B
| $6.38M | ﹤0.01% |
1,463,600
+66,200
| +5% | +$382K |
|
1123
PUT
Lattice Semiconductor
LSCC
$18.9B
| $6.37M | ﹤0.01% |
86,600
-500
| -0.6% | -$35.6K |
|
|
PSKY
1124
PUT
Paramount Skydance Corp
PSKY
$9.5B
| $6.37M | ﹤0.01% |
475,200
-226,300
| -32% | -$3.53M |
|
1125
PUT
Archer Aviation
ACHR
$3.9B
| $6.34M | ﹤0.01% |
843,000
-615,700
| -42% | -$5.79M |
|
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.