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 | |
|---|---|---|---|---|---|---|
2801
CALL
Array Technologies
ARRY
$818M
| $840K | ﹤0.01% |
91,100
-102,100
| -53% | -$876K |
|
|
ORLA
2802
CALL
Orla Mining
ORLA
$3.48B
| $839K | ﹤0.01% |
62,300
+46,400
| +292% | +$563K |
|
2803
iShares MSCI Australia ETF
EWA
$1.34B
| $837K | ﹤0.01% |
+31,962
| New | +$846K |
|
|
HELP
2804
CALL
Cybin Inc
HELP
$472M
| $836K | ﹤0.01% |
102,200
+8,600
| +9% | +$55.4K |
|
2805
CALL
Annexon
ANNX
$855M
| $835K | ﹤0.01% |
166,400
+151,100
| +988% | +$578K |
|
|
PENG
2806
PUT
Penguin Solutions Inc
PENG
$2.76B
| $835K | ﹤0.01% |
42,700
+1,600
| +4% | +$34.3K |
|
2807
PUT
Innovative Industrial Properties
IIPR
$1.78B
| $834K | ﹤0.01% |
17,600
-2,800
| -14% | -$145K |
|
2808
RH
RH
$3.3B
| $833K | ﹤0.01% |
4,652
-756
| -14% | -$129K |
|
2809
CALL
Scotiabank
BNS
$106B
| $833K | ﹤0.01% |
11,300
-44,200
| -80% | -$3M |
|
2810
PUT
Pampa Energía
PAM
$4.64B
| $832K | ﹤0.01% |
9,400
+9,100
| +3,033% | +$734K |
|
2811
CALL
Xylem
XYL
$28.5B
| $831K | ﹤0.01% |
6,100
+600
| +11% | +$86.3K |
|
2812
Vanda Pharmaceuticals
VNDA
$312M
| $830K | ﹤0.01% |
94,115
+62,436
| +197% | +$344K |
|
2813
Clorox
CLX
$11.6B
| $828K | ﹤0.01% |
8,211
+23
| +0.3% | +$2.5K |
|
2814
Neurocrine Biosciences
NBIX
$17.7B
| $828K | ﹤0.01% |
5,837
+2,939
| +101% | +$426K |
|
|
JHG
2815
CALL
DELISTED
Janus Henderson
JHG
| $828K | ﹤0.01% |
+17,400
| New | +$770K |
|
2816
Cadence Design Systems
CDNS
$90B
| $826K | ﹤0.01% |
+2,643
| New | +$862K |
|
2817
CALL
VeriSign
VRSN
$25.3B
| $826K | ﹤0.01% |
3,400
-2,600
| -43% | -$653K |
|
|
SUPV
2818
Grupo Supervielle
SUPV
$833M
| $826K | ﹤0.01% |
+69,847
| New | +$683K |
|
2819
Illumina
ILMN
$29.4B
| $823K | ﹤0.01% |
6,277
+3,839
| +157% | +$451K |
|
2820
Polaris
PII
$4.15B
| $823K | ﹤0.01% |
13,013
-35,496
| -73% | -$2.34M |
|
2821
PUT
United States Antimony
UAMY
$766M
| $821K | ﹤0.01% |
163,600
-881,500
| -84% | -$6.92M |
|
|
QXO
2822
QXO Inc
QXO
$14.2B
| $821K | ﹤0.01% |
42,568
-54,433
| -56% | -$1.04M |
|
2823
PUT
Innodata
INOD
$1.83B
| $820K | ﹤0.01% |
16,100
-32,700
| -67% | -$2.13M |
|
2824
CALL
Critical Metals Corp
CRML
$853M
| $817K | ﹤0.01% |
117,700
+69,600
| +145% | +$759K |
|
2825
Itaú Unibanco
ITUB
$91.3B
| $817K | ﹤0.01% |
+114,048
| New | +$811K |
|
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.