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 | |
|---|---|---|---|---|---|---|
|
CNTB
7751
PUT
Connect Biopharma Holdings
CNTB
$129M
| $2.54K | ﹤0.01% |
+900
| New | +$1.92K |
|
7752
James River Group Holdings
JRVR
$222M
| $2.54K | ﹤0.01% |
+399
| New | +$2.29K |
|
7753
CALL
SCYNEXIS
SCYX
$36M
| $2.53K | ﹤0.01% |
+500
| New | +$2.72K |
|
|
CRWU
7754
T-REX 2X Long CRWV Daily Target ETF
CRWU
$21.5M
| $2.52K | ﹤0.01% |
500
-4,130
| -89% | -$56.7K |
|
7755
PUT
BuzzFeed
BZFD
$102M
| $2.51K | ﹤0.01% |
2,700
-148,700
| -98% | -$188K |
|
7756
ProShares Trust UltraShort MSCI Japan
EWV
$6.09M
| $2.51K | ﹤0.01% |
+99
| New | +$2.59K |
|
7757
PUT
Tronox
TROX
$992M
| $2.5K | ﹤0.01% |
600
-315,900
| -100% | -$1.2M |
|
7758
VanEck Mortgage REIT Income ETF
MORT
$368M
| $2.49K | ﹤0.01% |
237
-6,521
| -96% | -$68.9K |
|
7759
PUT
Genesco
GCO
$427M
| $2.48K | ﹤0.01% |
100
-100
| -50% | -$2.87K |
|
7760
PUT
Cricut
CRCT
$989M
| $2.48K | ﹤0.01% |
500
-100
| -17% | -$511 |
|
7761
PUT
ReposiTrak
TRAK
$161M
| $2.47K | ﹤0.01% |
+200
| New | +$2.84K |
|
|
TRVG
7762
trivago
TRVG
$387M
| $2.47K | ﹤0.01% |
852
-7,776
| -90% | -$23.6K |
|
7763
CALL
Motorcar Parts of America
MPAA
$267M
| $2.47K | ﹤0.01% |
+200
| New | +$2.88K |
|
7764
CALL
Advantage Solutions
ADV
$547M
| $2.46K | ﹤0.01% |
112
+4
| +4% | +$116 |
|
|
NOTV
7765
DELISTED
Inotiv
NOTV
| $2.46K | ﹤0.01% |
4,384
+2,777
| +173% | +$2.9K |
|
7766
PUT
NETGEAR
NTGR
$662M
| $2.45K | ﹤0.01% |
100
-100
| -50% | -$2.88K |
|
7767
Arlo Technologies
ARLO
$1.55B
| $2.45K | ﹤0.01% |
+175
| New | +$2.75K |
|
7768
PSQ Holdings
PSQH
$11.3M
| $2.45K | ﹤0.01% |
158
-4,740
| -97% | -$117K |
|
7769
PUT
WisdomTree
WT
$2.97B
| $2.44K | ﹤0.01% |
200
| – | – |
|
7770
Sprott Gold Miners ETF
SGDM
$536M
| $2.44K | ﹤0.01% |
35
-1,867
| -98% | -$120K |
|
|
KQQQ
7771
CALL
Kurv Technology Titans Select ETF
KQQQ
$119M
| $2.42K | ﹤0.01% |
100
-1,700
| -94% | -$49.4K |
|
|
LKFT
7772
Lakefront Biotherapeutics American Depositary Shares
LKFT
$1.84B
| $2.42K | ﹤0.01% |
74
-180
| -71% | -$5.81K |
|
7773
Ispire Technology
ISPR
$91.3M
| $2.42K | ﹤0.01% |
864
+682
| +375% | +$1.58K |
|
7774
PUT
Outfront Media
OUT
$5.76B
| $2.41K | ﹤0.01% |
100
-400
| -80% | -$8.33K |
|
7775
Franklin Electric
FELE
$4.83B
| $2.39K | ﹤0.01% |
+25
| New | +$2.39K |
|
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.