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 | |
|---|---|---|---|---|---|---|
1601
CALL
Dycom Industries
DY
$12.9B
| $3.21M | ﹤0.01% |
9,500
| – | – |
|
|
GEMI
1602
CALL
Gemini Space Station
GEMI
$542M
| $3.21M | ﹤0.01% |
323,200
+99,900
| +45% | +$1.56M |
|
1603
CALL
KeyCorp
KEY
$24.3B
| $3.2M | ﹤0.01% |
155,200
-114,600
| -42% | -$2.13M |
|
1604
PUT
Royal Gold
RGLD
$17.1B
| $3.2M | ﹤0.01% |
14,400
-2,800
| -16% | -$555K |
|
1605
PUT
Ramaco Resources Class A
METC
$676M
| $3.2M | ﹤0.01% |
177,800
-14,600
| -8% | -$384K |
|
1606
PUT
CarMax
KMX
$8.27B
| $3.19M | ﹤0.01% |
82,600
-126,900
| -61% | -$5.07M |
|
1607
CALL
Digital Realty Trust
DLR
$73.7B
| $3.19M | ﹤0.01% |
20,600
-12,700
| -38% | -$2.09M |
|
1608
PUT
Chubb
CB
$140B
| $3.18M | ﹤0.01% |
10,200
-9,600
| -48% | -$2.81M |
|
1609
PUT
Warby Parker
WRBY
$3.01B
| $3.18M | ﹤0.01% |
146,100
+141,600
| +3,147% | +$3.08M |
|
1610
CALL
Klaviyo
KVYO
$4.91B
| $3.18M | ﹤0.01% |
97,900
-33,900
| -26% | -$950K |
|
1611
PUT
SentinelOne
S
$6.22B
| $3.18M | ﹤0.01% |
211,700
+74,300
| +54% | +$1.22M |
|
1612
PUT
iShares Convertible Bond ETF
ICVT
$7.23B
| $3.17M | ﹤0.01% |
85,400
-47,700
| -36% | -$4.79M |
|
1613
CALL
Fortuna Silver Mines
FSM
$2.59B
| $3.17M | ﹤0.01% |
323,400
-254,900
| -44% | -$2.29M |
|
1614
Rockwell Automation
ROK
$51.4B
| $3.17M | ﹤0.01% |
+8,146
| New | +$3.06M |
|
1615
PUT
American Conservative Values ETF
ACVF
$149M
| $3.17M | ﹤0.01% |
250,900
-574,100
| -70% | -$28.2M |
|
|
TIGR
1616
UP Fintech Holding
TIGR
$845M
| $3.16M | ﹤0.01% |
330,741
-268,381
| -45% | -$2.56M |
|
1617
PUT
Antero Resources
AR
$10.9B
| $3.16M | ﹤0.01% |
91,700
-72,300
| -44% | -$2.45M |
|
1618
PUT
McEwen Inc
MUX
$1.03B
| $3.15M | ﹤0.01% |
170,300
-20,200
| -11% | -$376K |
|
1619
PUT
XP
XP
$8.62B
| $3.15M | ﹤0.01% |
192,400
+45,100
| +31% | +$794K |
|
1620
CALL
Xcel Energy
XEL
$51B
| $3.15M | ﹤0.01% |
42,600
+30,600
| +255% | +$2.41M |
|
1621
PUT
Nokia
NOK
$50.8B
| $3.13M | ﹤0.01% |
484,500
+394,900
| +441% | +$2.45M |
|
|
ETOR
1622
CALL
eToro Group
ETOR
$2.93B
| $3.13M | ﹤0.01% |
89,000
+60,400
| +211% | +$2.33M |
|
1623
CALL
Cardinal Health
CAH
$53.4B
| $3.12M | ﹤0.01% |
15,200
-55,900
| -79% | -$10.5M |
|
1624
Roivant Sciences
ROIV
$25.2B
| $3.12M | ﹤0.01% |
143,897
+98,669
| +218% | +$1.95M |
|
1625
CALL
Incyte
INCY
$23.5B
| $3.12M | ﹤0.01% |
31,600
+21,000
| +198% | +$2.03M |
|
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.