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 | |
|---|---|---|---|---|---|---|
3301
Global X MSCI Argentina ETF
ARGT
$837M
| $501K | ﹤0.01% |
+5,481
| New | +$468K |
|
3302
CALL
Cadiz
CDZI
$247M
| $501K | ﹤0.01% |
89,300
+63,600
| +247% | +$341K |
|
3303
CALL
GoodRx Holdings
GDRX
$1.05B
| $501K | ﹤0.01% |
184,800
+153,500
| +490% | +$504K |
|
|
EXK
3304
PUT
Endeavour Silver
EXK
$2.23B
| $500K | ﹤0.01% |
53,200
-32,500
| -38% | -$276K |
|
3305
Teucrium Soybean Fund
SOYB
$62.3M
| $499K | ﹤0.01% |
22,839
+14,801
| +184% | +$335K |
|
|
ABVX
3306
CALL
Abivax
ABVX
$10.7B
| $499K | ﹤0.01% |
+3,700
| New | +$404K |
|
3307
CALL
Enovis
ENOV
$1.69B
| $498K | ﹤0.01% |
18,700
+17,700
| +1,770% | +$523K |
|
3308
PUT
Equity Residential
EQR
$25.6B
| $498K | ﹤0.01% |
7,900
-35,800
| -82% | -$2.2M |
|
3309
Owens Corning
OC
$11.6B
| $497K | ﹤0.01% |
+4,439
| New | +$521K |
|
3310
Shake Shack
SHAK
$2.53B
| $496K | ﹤0.01% |
6,113
-10,103
| -62% | -$891K |
|
3311
CALL
Sprinklr
CXM
$1.49B
| $496K | ﹤0.01% |
63,700
+10,500
| +20% | +$79.9K |
|
|
VG
3312
Venture Global Inc
VG
$31.2B
| $494K | ﹤0.01% |
72,391
+35,621
| +97% | +$297K |
|
3313
CALL
Atlas Energy Solutions
AESI
$1.35B
| $494K | ﹤0.01% |
52,400
+16,000
| +44% | +$162K |
|
|
ARIS
3314
CALL
Aris Mining
ARIS
$2.93B
| $493K | ﹤0.01% |
30,400
+12,800
| +73% | +$157K |
|
3315
PUT
Amprius Technologies
AMPX
$1.24B
| $493K | ﹤0.01% |
62,500
-12,500
| -17% | -$143K |
|
3316
PUT
Vornado Realty Trust
VNO
$7.37B
| $493K | ﹤0.01% |
14,800
-5,400
| -27% | -$197K |
|
3317
Anterix
ATEX
$1.71B
| $492K | ﹤0.01% |
22,550
+19,582
| +660% | +$407K |
|
3318
CALL
Varonis Systems
VRNS
$5.18B
| $492K | ﹤0.01% |
15,000
+9,500
| +173% | +$399K |
|
|
WAY
3319
PUT
Waystar Holding Corp
WAY
$4.64B
| $491K | ﹤0.01% |
15,000
-24,900
| -62% | -$887K |
|
|
CYBR
3320
CALL
DELISTED
CyberArk
CYBR
| $491K | ﹤0.01% |
1,100
-4,300
| -80% | -$2.07M |
|
3321
CALL
Universal Display
OLED
$3.81B
| $490K | ﹤0.01% |
4,200
-18,000
| -81% | -$2.33M |
|
3322
PUT
Groupon
GRPN
$1.04B
| $490K | ﹤0.01% |
27,800
-58,000
| -68% | -$1.09M |
|
3323
Rogers Corp
ROG
$2.14B
| $488K | ﹤0.01% |
5,330
-1,101
| -17% | -$94.5K |
|
3324
CALL
Credit Acceptance
CACC
$5.78B
| $488K | ﹤0.01% |
1,100
-3,700
| -77% | -$1.72M |
|
|
VZLA
3325
Vizsla Silver
VZLA
$1.1B
| $487K | ﹤0.01% |
89,091
+79,864
| +866% | +$375K |
|
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.