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 | |
|---|---|---|---|---|---|---|
4651
CALL
STAAR Surgical
STAA
$1.19B
| $136K | ﹤0.01% |
5,900
-2,600
| -31% | -$67K |
|
|
VWAV
4652
CALL
VisionWave Holdings
VWAV
$57.6M
| $136K | ﹤0.01% |
14,700
-12,000
| -45% | -$125K |
|
4653
SI-BONE Inc
SIBN
$818M
| $136K | ﹤0.01% |
6,897
+6,870
| +25,444% | +$119K |
|
4654
Hycroft Mining Holding Corp
HYMC
$1.79B
| $136K | ﹤0.01% |
+5,720
| New | +$63.3K |
|
4655
Hyster-Yale Materials Handling
HY
$576M
| $136K | ﹤0.01% |
+4,572
| New | +$151K |
|
4656
PUT
Village Farms International
VFF
$240M
| $136K | ﹤0.01% |
37,200
-55,700
| -60% | -$194K |
|
4657
PUT
RingCentral
RNG
$4.83B
| $136K | ﹤0.01% |
4,700
-24,100
| -84% | -$686K |
|
|
TECX
4658
PUT
Tectonic Therapeutic
TECX
$536M
| $136K | ﹤0.01% |
6,500
| – | – |
|
4659
CALL
Brown & Brown
BRO
$25.1B
| $135K | ﹤0.01% |
1,700
-400
| -19% | -$33.4K |
|
4660
PUT
Mistras Group
MG
$477M
| $135K | ﹤0.01% |
10,700
-47,800
| -82% | -$539K |
|
4661
CALL
Eton Pharmaceutcials
ETON
$1.32B
| $135K | ﹤0.01% |
8,000
+200
| +3% | +$3.52K |
|
4662
CALL
Camping World
CWH
$384M
| $135K | ﹤0.01% |
13,900
-15,000
| -52% | -$186K |
|
4663
CALL
Caleres
CAL
$432M
| $135K | ﹤0.01% |
11,100
-26,500
| -70% | -$326K |
|
4664
Tronox
TROX
$967M
| $135K | ﹤0.01% |
32,347
-53,642
| -62% | -$204K |
|
4665
PUT
James Hardie Industries
JHX
$15.2B
| $135K | ﹤0.01% |
6,500
+1,200
| +23% | +$24.1K |
|
4666
Louisiana-Pacific
LPX
$5.14B
| $135K | ﹤0.01% |
+1,670
| New | +$141K |
|
|
SSK
4667
REX-Osprey SOL + Staking ETF
SSK
$68.7M
| $135K | ﹤0.01% |
7,076
+5,730
| +426% | +$142K |
|
4668
CALL
EPR Properties
EPR
$4.89B
| $135K | ﹤0.01% |
2,700
-9,200
| -77% | -$479K |
|
4669
Butterfly Network
BFLY
$1.86B
| $135K | ﹤0.01% |
35,425
-59,655
| -63% | -$162K |
|
4670
PUT
Allegro MicroSystems
ALGM
$7.86B
| $135K | ﹤0.01% |
5,100
-11,500
| -69% | -$316K |
|
|
LAND
4671
PUT
Gladstone Land Corp
LAND
$365M
| $135K | ﹤0.01% |
14,700
+5,700
| +63% | +$52.2K |
|
4672
PUT
Savers
SVV
$1.53B
| $134K | ﹤0.01% |
14,400
+14,300
| +14,300% | +$147K |
|
4673
CALL
Designer Brands
DBI
$315M
| $134K | ﹤0.01% |
18,100
-47,800
| -73% | -$230K |
|
4674
Ovintiv
OVV
$17B
| $134K | ﹤0.01% |
3,431
-11,760
| -77% | -$456K |
|
|
GLNK
4675
Grayscale Chainlink Trust ETF
GLNK
$75.8M
| $134K | ﹤0.01% |
+12,317
| New | +$143K |
|
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.