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 | |
|---|---|---|---|---|---|---|
2051
CALL
LKQ Corp
LKQ
$6.58B
| $1.83M | ﹤0.01% |
60,600
+11,100
| +22% | +$335K |
|
2052
PUT
Ocular Therapeutix
OCUL
$1.86B
| $1.83M | ﹤0.01% |
150,600
+106,100
| +238% | +$1.29M |
|
|
CRON
2053
CALL
Cronos Group
CRON
$1.05B
| $1.83M | ﹤0.01% |
694,500
+440,100
| +173% | +$1.14M |
|
|
DX
2054
PUT
Dynex Capital
DX
$2.99B
| $1.82M | ﹤0.01% |
130,200
+52,000
| +66% | +$702K |
|
|
SUPV
2055
PUT
Grupo Supervielle
SUPV
$833M
| $1.82M | ﹤0.01% |
154,300
+114,600
| +289% | +$1.12M |
|
|
KDK
2056
CALL
Kodiak AI
KDK
$802M
| $1.82M | ﹤0.01% |
166,800
+95,400
| +134% | +$764K |
|
2057
ProShares UltraPro Short S&P 500
SPXU
$436M
| $1.82M | ﹤0.01% |
36,620
-15,281
| -29% | -$794K |
|
2058
CALL
TPG
TPG
$6.87B
| $1.82M | ﹤0.01% |
28,500
-61,700
| -68% | -$3.64M |
|
2059
Direxion Daily Technology Bull 3x ETF
TECL
$5.14B
| $1.82M | ﹤0.01% |
15,468
+10,726
| +226% | +$1.37M |
|
2060
CALL
CBRE Group
CBRE
$40.8B
| $1.82M | ﹤0.01% |
11,300
+8,600
| +319% | +$1.35M |
|
|
VSXY
2061
PUT
Victoria's Secret
VSXY
$6.64B
| $1.81M | ﹤0.01% |
33,500
-45,000
| -57% | -$1.79M |
|
2062
CALL
Maximus
MMS
$3.14B
| $1.81M | ﹤0.01% |
21,000
+1,000
| +5% | +$85.5K |
|
2063
GraniteShares ETF Trust GraniteShares 2x Long META Daily ETF
FBL
$179M
| $1.81M | ﹤0.01% |
55,753
+43,981
| +374% | +$1.54M |
|
2064
PUT
UGI
UGI
$8B
| $1.81M | ﹤0.01% |
48,400
-110,500
| -70% | -$3.91M |
|
2065
PUT
Calumet Specialty Products
CLMT
$3.63B
| $1.81M | ﹤0.01% |
91,000
-49,200
| -35% | -$947K |
|
2066
Agnico Eagle Mines
AEM
$72.6B
| $1.8M | ﹤0.01% |
+10,646
| New | +$1.79M |
|
2067
Fox Class A
FOXA
$23.2B
| $1.8M | ﹤0.01% |
24,697
+13,831
| +127% | +$904K |
|
|
MRP
2068
PUT
Millrose Properties Inc
MRP
$4.74B
| $1.8M | ﹤0.01% |
60,400
-147,100
| -71% | -$4.61M |
|
2069
PUT
Birkenstock
BIRK
$7.47B
| $1.8M | ﹤0.01% |
44,100
-91,000
| -67% | -$3.85M |
|
2070
CALL
Wendy's
WEN
$1.33B
| $1.8M | ﹤0.01% |
216,400
+67,500
| +45% | +$582K |
|
2071
Western Union
WU
$2.57B
| $1.8M | ﹤0.01% |
193,562
+22,921
| +13% | +$202K |
|
2072
Nice
NICE
$5.29B
| $1.8M | ﹤0.01% |
15,937
+112
| +0.7% | +$13.5K |
|
2073
CALL
Atour Lifestyle Holdings
ATAT
$4.35B
| $1.8M | ﹤0.01% |
45,700
+31,100
| +213% | +$1.22M |
|
|
TPC
2074
CALL
Tutor Perini Cor
TPC
$4.57B
| $1.8M | ﹤0.01% |
26,800
-61,500
| -70% | -$4.03M |
|
2075
PUT
Kodiak Gas Services
KGS
$5.96B
| $1.8M | ﹤0.01% |
48,000
-22,900
| -32% | -$810K |
|
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.