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 | |
|---|---|---|---|---|---|---|
5001
Avista
AVA
$3.34B
| $100K | ﹤0.01% |
2,596
+2,451
| +1,690% | +$95.7K |
|
|
WW
5002
CALL
WW International
WW
$144M
| $99.8K | ﹤0.01% |
133,200
-15,400
| -10% | -$430K |
|
5003
PUT
Charles River Laboratories
CRL
$11.2B
| $99.7K | ﹤0.01% |
500
-2,800
| -85% | -$508K |
|
5004
CALL
Black Stone Minerals
BSM
$3.18B
| $99.7K | ﹤0.01% |
7,500
-11,400
| -60% | -$154K |
|
5005
SFL Corp
SFL
$1.64B
| $99.5K | ﹤0.01% |
12,740
-21,980
| -63% | -$169K |
|
5006
RELX
RELX
$61.8B
| $99.5K | ﹤0.01% |
2,461
+2,179
| +773% | +$93K |
|
5007
CALL
Stepan Co
SCL
$1.46B
| $99.5K | ﹤0.01% |
+2,100
| New | +$96.2K |
|
5008
CALL
Spire
SR
$4.72B
| $99.2K | ﹤0.01% |
1,200
-2,200
| -65% | -$188K |
|
|
RPC
5009
PUT
Ridgepost Capital
RPC
$949M
| $99.1K | ﹤0.01% |
10,100
+1,400
| +16% | +$14.2K |
|
5010
PUT
Korn Ferry
KFY
$4.18B
| $99K | ﹤0.01% |
1,500
-17,200
| -92% | -$1.16M |
|
|
HELP
5011
PUT
Cybin Inc
HELP
$485M
| $99K | ﹤0.01% |
12,100
+6,600
| +120% | +$42.5K |
|
5012
IDEAYA Biosciences
IDYA
$3.42B
| $98.9K | ﹤0.01% |
2,862
+1,740
| +155% | +$55.5K |
|
5013
Xencor
XNCR
$1.5B
| $98.9K | ﹤0.01% |
+6,460
| New | +$96.5K |
|
|
BETA
5014
CALL
Beta Technologies Inc
BETA
$4.37B
| $98.7K | ﹤0.01% |
+3,500
| New | +$104K |
|
5015
PUT
Genmab
GMAB
$17.7B
| $98.6K | ﹤0.01% |
3,200
-4,700
| -59% | -$146K |
|
|
TOPT
5016
iShares Top 20 U.S. Stocks ETF
TOPT
$665M
| $98.5K | ﹤0.01% |
3,155
+2,475
| +364% | +$76.7K |
|
5017
CALL
Magnolia Oil & Gas
MGY
$6.09B
| $98.5K | ﹤0.01% |
4,500
-4,900
| -52% | -$111K |
|
|
AIOT
5018
CALL
PowerFleet Inc
AIOT
$526M
| $98.4K | ﹤0.01% |
18,500
+14,700
| +387% | +$75.2K |
|
5019
Saratoga Investment
SAR
$312M
| $98.4K | ﹤0.01% |
4,264
+1,435
| +51% | +$32.5K |
|
5020
CALL
Schneider National
SNDR
$6.26B
| $98.2K | ﹤0.01% |
+3,700
| New | +$87.3K |
|
5021
PUT
indie Semiconductor
INDI
$682M
| $98.1K | ﹤0.01% |
27,800
-88,000
| -76% | -$386K |
|
5022
PUT
Ameriprise Financial
AMP
$48.3B
| $98.1K | ﹤0.01% |
200
-2,800
| -93% | -$1.33M |
|
5023
CALL
Universal Insurance Holdings
UVE
$1.22B
| $98K | ﹤0.01% |
2,900
-1,300
| -31% | -$41.5K |
|
|
AVL
5024
Direxion Daily AVGO Bull 2X ETF
AVL
$201M
| $98K | ﹤0.01% |
+2,222
| New | +$127K |
|
|
TUYA
5025
PUT
Tuya Inc
TUYA
$1.03B
| $97.9K | ﹤0.01% |
46,400
+11,800
| +34% | +$26.9K |
|
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.