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 | |
|---|---|---|---|---|---|---|
3851
Direxion Daily Gold Miners Index Bull 2X ETF
NUGT
$814M
| $291K | ﹤0.01% |
+1,583
| New | +$253K |
|
3852
PUT
Arbutus Biopharma
ABUS
$857M
| $291K | ﹤0.01% |
60,400
+40,800
| +208% | +$183K |
|
3853
PUT
Manulife Financial
MFC
$73.5B
| $290K | ﹤0.01% |
8,000
+2,700
| +51% | +$91.6K |
|
3854
CALL
MarketAxess Holdings
MKTX
$4.39B
| $290K | ﹤0.01% |
1,600
-500
| -24% | -$85.3K |
|
3855
RB Global
RBA
$21.5B
| $290K | ﹤0.01% |
2,815
-4,573
| -62% | -$465K |
|
|
TUZ
3856
PUT
DELISTED
PIMCO 1-3 Year U.S. Treasury Index Exchange-Traded Fund
TUZ
| $289K | ﹤0.01% |
4,500
+1,400
| +45% | +$90K |
|
3857
CALL
Erasca
ERAS
$6.16B
| $289K | ﹤0.01% |
77,700
+76,200
| +5,080% | +$214K |
|
|
JBIO
3858
PUT
Jade Biosciences
JBIO
$1.19B
| $289K | ﹤0.01% |
18,700
-5,000
| -21% | -$58.7K |
|
3859
CALL
Baytex Energy
BTE
$2.97B
| $288K | ﹤0.01% |
89,100
+75,400
| +550% | +$210K |
|
|
TGEN
3860
PUT
Tecogen Inc
TGEN
$93M
| $288K | ﹤0.01% |
58,200
-31,200
| -35% | -$234K |
|
3861
US Foods
USFD
$22.8B
| $287K | ﹤0.01% |
+3,817
| New | +$287K |
|
|
GAMB
3862
CALL
DELISTED
Gambling.com
GAMB
| $287K | ﹤0.01% |
52,600
+42,600
| +426% | +$271K |
|
3863
CALL
Blend Labs
BLND
$433M
| $287K | ﹤0.01% |
94,300
-31,000
| -25% | -$98.9K |
|
3864
iShares US Broker-Dealers & Securities Exchanges ETF
IAI
$1.36B
| $287K | ﹤0.01% |
+1,598
| New | +$281K |
|
3865
Editas Medicine
EDIT
$396M
| $287K | ﹤0.01% |
139,772
-92,091
| -40% | -$266K |
|
3866
HCA Healthcare
HCA
$90.6B
| $286K | ﹤0.01% |
+613
| New | +$285K |
|
3867
CALL
Teradata
TDC
$2.9B
| $286K | ﹤0.01% |
9,400
-19,900
| -68% | -$521K |
|
3868
CALL
AnaptysBio
ANAB
$1.52B
| $286K | ﹤0.01% |
5,900
+2,100
| +55% | +$81.9K |
|
3869
CALL
EVgo
EVGO
$224M
| $286K | ﹤0.01% |
98,200
-63,000
| -39% | -$229K |
|
3870
CALL
Genworth Financial
GNW
$3.83B
| $285K | ﹤0.01% |
31,600
-200
| -0.6% | -$1.74K |
|
3871
CALL
Paysign
PAYS
$506M
| $285K | ﹤0.01% |
55,300
-11,500
| -17% | -$62K |
|
3872
GraniteShares 2x Long COIN Daily ETF
CONL
$531M
| $285K | ﹤0.01% |
19,427
+18,124
| +1,391% | +$510K |
|
|
SMU
3873
CALL
Tradr 2X Long SMR Daily ETF
SMU
$45.5M
| $284K | ﹤0.01% |
2,333
+1,380
| +145% | +$261K |
|
3874
PUT
Ryman Hospitality Properties
RHP
$8.62B
| $284K | ﹤0.01% |
+3,000
| New | +$277K |
|
3875
Grid Dynamics Holdings
GDYN
$532M
| $284K | ﹤0.01% |
31,409
+28,733
| +1,074% | +$249K |
|
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.