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 | |
|---|---|---|---|---|---|---|
7026
CALL
Tenable Holdings
TENB
$3.59B
| $9.41K | ﹤0.01% |
400
-900
| -69% | -$24.6K |
|
7027
PUT
Huazhu Hotels Group
HTHT
$13B
| $9.41K | ﹤0.01% |
200
-200
| -50% | -$8.63K |
|
7028
PUT
Laser Photonics
LASE
$49.2M
| $9.39K | ﹤0.01% |
3,800
-54,000
| -93% | -$181K |
|
7029
HNI Corp
HNI
$3.14B
| $9.37K | ﹤0.01% |
223
-5,749
| -96% | -$243K |
|
7030
PUT
Northwest Natural Holdings
NWN
$2.11B
| $9.35K | ﹤0.01% |
200
-2,900
| -94% | -$135K |
|
7031
PUT
Backblaze
BLZE
$758M
| $9.32K | ﹤0.01% |
+2,000
| New | +$13.7K |
|
7032
PUT
Marcus Corp
MCS
$912M
| $9.31K | ﹤0.01% |
600
-1,000
| -63% | -$14.9K |
|
|
TRIB
7033
CALL
Trinity Biotech
TRIB
$8.61M
| $9.25K | ﹤0.01% |
390
+73
| +23% | +$2.15K |
|
7034
PUT
Journey Medical
DERM
$178M
| $9.25K | ﹤0.01% |
+1,200
| New | +$9.41K |
|
|
WIMI
7035
CALL
WiMi Hologram Cloud
WIMI
$22.2M
| $9.24K | ﹤0.01% |
3,900
-11,000
| -74% | -$37.3K |
|
|
HTT
7036
PUT
High Templar Tech Ltd
HTT
$379M
| $9.23K | ﹤0.01% |
2,600
-300
| -10% | -$1.34K |
|
7037
Harvard Bioscience
HBIO
$27.5M
| $9.22K | ﹤0.01% |
1,379
+1,104
| +401% | +$6.55K |
|
7038
CALL
First Trust Value Line Dividend Fund
FVD
$8.33B
| $9.22K | ﹤0.01% |
200
| – | – |
|
7039
PUT
INmune Bio
INMB
$47.1M
| $9.2K | ﹤0.01% |
5,900
-11,900
| -67% | -$21.2K |
|
7040
Genesco
GCO
$429M
| $9.19K | ﹤0.01% |
+371
| New | +$10.6K |
|
7041
CALL
John Wiley & Sons Class A
WLY
$2.66B
| $9.19K | ﹤0.01% |
300
-200
| -40% | -$7.04K |
|
7042
PUT
Xencor
XNCR
$1.59B
| $9.19K | ﹤0.01% |
+600
| New | +$8.96K |
|
7043
PUT
MillerKnoll
MLKN
$1.53B
| $9.14K | ﹤0.01% |
500
| – | – |
|
7044
Alliant Energy
LNT
$18.3B
| $9.1K | ﹤0.01% |
140
-11,316
| -99% | -$758K |
|
|
INVX
7045
Innovex International
INVX
$1.85B
| $9.1K | ﹤0.01% |
416
-138
| -25% | -$2.88K |
|
7046
VirTra
VTSI
$35.7M
| $9.07K | ﹤0.01% |
2,160
-2,366
| -52% | -$12.4K |
|
7047
Guidewire Software
GWRE
$12.8B
| $9.04K | ﹤0.01% |
+45
| New | +$9.95K |
|
7048
CALL
ALX Oncology
ALXO
$262M
| $9.04K | ﹤0.01% |
8,000
-43,900
| -85% | -$66.5K |
|
7049
PUT
Heartland Express
HTLD
$986M
| $9.03K | ﹤0.01% |
1,000
-1,500
| -60% | -$12.5K |
|
7050
Liberty Media Series A
FWONA
$23.1B
| $9.03K | ﹤0.01% |
101
+23
| +29% | +$2.06K |
|
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.