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 | |
|---|---|---|---|---|---|---|
|
SII
4301
PUT
Sprott
SII
$2.68B
| $186K | ﹤0.01% |
1,900
-400
| -17% | -$35.5K |
|
4302
PUT
Prospect Capital
PSEC
$1.08B
| $186K | ﹤0.01% |
71,800
-448,400
| -86% | -$1.2M |
|
4303
PUT
Champion Homes
SKY
$4.41B
| $186K | ﹤0.01% |
2,200
+600
| +38% | +$47.3K |
|
4304
CALL
IHS Holding
IHS
$2.78B
| $186K | ﹤0.01% |
24,900
+11,000
| +79% | +$75.7K |
|
4305
PUT
State Street Multi-Asset Real Return ETF
RLY
$1.26B
| $186K | ﹤0.01% |
+4,500
| New | +$141K |
|
4306
PUT
CAE Inc. Common Shares
CAE
$8.44B
| $186K | ﹤0.01% |
6,100
-100
| -2% | -$2.81K |
|
4307
Brown-Forman Class B
BF.B
$13.5B
| $185K | ﹤0.01% |
7,115
-5,246
| -42% | -$148K |
|
4308
PUT
Warrior Met Coal
HCC
$4.17B
| $185K | ﹤0.01% |
2,100
-13,700
| -87% | -$1.03M |
|
4309
PUT
Vitesse Energy
VTS
$644M
| $185K | ﹤0.01% |
9,600
-4,700
| -33% | -$100K |
|
4310
PUT
Axcelis
ACLS
$3.44B
| $185K | ﹤0.01% |
2,300
-15,200
| -87% | -$1.27M |
|
4311
Dover
DOV
$26.7B
| $185K | ﹤0.01% |
945
+337
| +55% | +$61.4K |
|
|
SNCY
4312
CALL
DELISTED
Sun Country Airlines
SNCY
| $184K | ﹤0.01% |
12,800
-4,200
| -25% | -$53.7K |
|
4313
CALL
Rigel Pharmaceuticals
RIGL
$723M
| $184K | ﹤0.01% |
4,300
+2,400
| +126% | +$90.5K |
|
4314
PUT
Coca-Cola Consolidated
COKE
$12.8B
| $184K | ﹤0.01% |
1,200
+800
| +200% | +$117K |
|
|
CWVX
4315
CALL
Tradr 2X Long CRWV Daily ETF
CWVX
$51.4M
| $184K | ﹤0.01% |
+6,000
| New | +$339K |
|
4316
First Industrial Realty Trust
FR
$8.66B
| $184K | ﹤0.01% |
+3,211
| New | +$179K |
|
|
LOMA
4317
PUT
Loma Negra
LOMA
$1.34B
| $184K | ﹤0.01% |
+14,200
| New | +$152K |
|
4318
CALL
Axogen
AXGN
$2.2B
| $183K | ﹤0.01% |
5,600
-41,300
| -88% | -$1.02M |
|
4319
CALL
Avita Medical
RCEL
$137M
| $183K | ﹤0.01% |
53,100
-39,100
| -42% | -$156K |
|
4320
PUT
ProPetro Holding
PUMP
$1.25B
| $183K | ﹤0.01% |
+19,200
| New | +$167K |
|
4321
PUT
MiMedx Group
MDXG
$630M
| $182K | ﹤0.01% |
26,900
-35,800
| -57% | -$251K |
|
4322
CALL
California Water Service
CWT
$3.1B
| $182K | ﹤0.01% |
4,200
+3,900
| +1,300% | +$178K |
|
|
SGMO
4323
CALL
DELISTED
SANGAMO THERAPEUTICS INC
SGMO
| $182K | ﹤0.01% |
432,500
+21,200
| +5% | +$11.2K |
|
4324
CALL
Gladstone Investment Corp
GAIN
$642M
| $182K | ﹤0.01% |
13,000
+10,200
| +364% | +$141K |
|
|
TGR
4325
PUT
DELISTED
ISHARES TARGET DATE RETIREMENT INCOME ETF
TGR
| $181K | ﹤0.01% |
3,600
-9,700
| -73% | -$489K |
|
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.