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 | |
|---|---|---|---|---|---|---|
7176
Schwab 5-10 Year Corporate Bond ETF
SCHI
$11.5B
| $7.46K | ﹤0.01% |
325
+25
| +8% | +$576 |
|
7177
Stantec
STN
$8.17B
| $7.45K | ﹤0.01% |
79
-350
| -82% | -$36K |
|
7178
CALL
Unisys
UIS
$252M
| $7.45K | ﹤0.01% |
2,700
-36,200
| -93% | -$113K |
|
7179
Ribbon Communications
RBBN
$386M
| $7.45K | ﹤0.01% |
2,586
-17,356
| -87% | -$56K |
|
7180
Koppers
KOP
$946M
| $7.45K | ﹤0.01% |
275
-714
| -72% | -$20K |
|
7181
CALL
BuzzFeed
BZFD
$99M
| $7.44K | ﹤0.01% |
8,000
+700
| +10% | +$885 |
|
7182
CALL
CXApp
CXAI
$12.9M
| $7.44K | ﹤0.01% |
22,400
+17,300
| +339% | +$9.93K |
|
7183
CALL
Epsilon Energy
EPSN
$168M
| $7.42K | ﹤0.01% |
1,600
-900
| -36% | -$4.34K |
|
7184
PUT
ADC Therapeutics
ADCT
$140M
| $7.41K | ﹤0.01% |
2,100
-20,500
| -91% | -$83.2K |
|
|
VWAV
7185
PUT
VisionWave Holdings
VWAV
$57.6M
| $7.41K | ﹤0.01% |
800
| – | – |
|
7186
CALL
Nkarta
NKTX
$152M
| $7.4K | ﹤0.01% |
+4,000
| New | +$8K |
|
|
PVL
7187
PUT
Permianville Royalty Trust
PVL
$55.8M
| $7.38K | ﹤0.01% |
4,100
| – | – |
|
7188
CALL
Tennant Co
TNC
$1.44B
| $7.37K | ﹤0.01% |
+100
| New | +$7.64K |
|
7189
PUT
New Mountain Finance
NMFC
$654M
| $7.37K | ﹤0.01% |
800
-1,200
| -60% | -$11.3K |
|
7190
PUT
Goosehead Insurance
GSHD
$2.51B
| $7.37K | ﹤0.01% |
+100
| New | +$7.13K |
|
|
NOTV
7191
PUT
DELISTED
Inotiv
NOTV
| $7.36K | ﹤0.01% |
+13,100
| New | +$13.7K |
|
|
OBE
7192
PUT
Obsidian Energy
OBE
$656M
| $7.36K | ﹤0.01% |
1,200
+800
| +200% | +$4.84K |
|
7193
Chegg
CHGG
$116M
| $7.34K | ﹤0.01% |
+7,894
| New | +$8.61K |
|
|
ABVE
7194
CALL
DELISTED
Above Food Ingredients Inc
ABVE
| $7.33K | ﹤0.01% |
+4,500
| New | +$13.5K |
|
7195
CALL
Bristow Group
VTOL
$1.33B
| $7.32K | ﹤0.01% |
+200
| New | +$7.53K |
|
7196
Direxion Daily MSFT Bear 1X ETF
MSFD
$10.1M
| $7.31K | ﹤0.01% |
+635
| New | +$7.1K |
|
7197
PUT
Greenlight Captial
GLRE
$579M
| $7.29K | ﹤0.01% |
500
| – | – |
|
7198
PUT
Ispire Technology
ISPR
$86.1M
| $7.28K | ﹤0.01% |
+2,600
| New | +$6.04K |
|
|
ACH
7199
PUT
Accendra Health
ACH
$254M
| $7.28K | ﹤0.01% |
2,600
-10,900
| -81% | -$39K |
|
7200
CALL
MarineMax
HZO
$748M
| $7.27K | ﹤0.01% |
300
-300
| -50% | -$7.4K |
|
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.