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 | |
|---|---|---|---|---|---|---|
2401
PUT
Agios Pharmaceuticals
AGIO
$2.16B
| $1.26M | ﹤0.01% |
46,400
+31,900
| +220% | +$1.12M |
|
2402
PUT
Avantor
AVTR
$7.81B
| $1.26M | ﹤0.01% |
110,100
-95,300
| -46% | -$1.17M |
|
2403
CALL
Vita Coco
COCO
$3.77B
| $1.26M | ﹤0.01% |
23,800
+22,500
| +1,731% | +$1.06M |
|
2404
PUT
Axos Financial
AX
$5.45B
| $1.26M | ﹤0.01% |
14,600
-300
| -2% | -$24.7K |
|
2405
Northrop Grumman
NOC
$77B
| $1.26M | ﹤0.01% |
+2,206
| New | +$1.28M |
|
2406
PUT
Frontline
FRO
$8.75B
| $1.26M | ﹤0.01% |
57,600
-164,000
| -74% | -$3.83M |
|
2407
Janus Henderson B-BBB CLO ETF
JBBB
$1.4B
| $1.26M | ﹤0.01% |
26,338
+22,488
| +584% | +$1.08M |
|
2408
CALL
Iron Mountain
IRM
$38.2B
| $1.25M | ﹤0.01% |
15,100
-12,000
| -44% | -$1.12M |
|
2409
PUT
Domino's
DPZ
$11B
| $1.25M | ﹤0.01% |
3,000
-3,300
| -52% | -$1.38M |
|
|
CYBR
2410
PUT
DELISTED
CyberArk
CYBR
| $1.25M | ﹤0.01% |
2,800
-2,100
| -43% | -$1.01M |
|
|
PONY
2411
Pony AI Inc
PONY
$3.1B
| $1.25M | ﹤0.01% |
+86,008
| New | +$1.43M |
|
2412
CALL
Ferguson
FERG
$44.7B
| $1.25M | ﹤0.01% |
5,600
-1,700
| -23% | -$406K |
|
2413
PUT
Redwire
RDW
$2.08B
| $1.25M | ﹤0.01% |
164,000
-124,800
| -43% | -$916K |
|
2414
PUT
Alamos Gold
AGI
$12.4B
| $1.25M | ﹤0.01% |
32,300
-6,900
| -18% | -$240K |
|
2415
BigBear.ai
BBAI
$1.32B
| $1.24M | ﹤0.01% |
230,225
-187,483
| -45% | -$1.22M |
|
2416
PUT
Northern Trust
NTRS
$22.2B
| $1.24M | ﹤0.01% |
9,100
-14,600
| -62% | -$1.92M |
|
2417
CALL
Merit Medical Systems
MMSI
$4.43B
| $1.24M | ﹤0.01% |
14,100
-5,200
| -27% | -$443K |
|
2418
CALL
Root
ROOT
$917M
| $1.24M | ﹤0.01% |
17,200
-15,600
| -48% | -$1.24M |
|
2419
PUT
Syndax Pharmaceuticals
SNDX
$1.84B
| $1.24M | ﹤0.01% |
59,100
-11,000
| -16% | -$192K |
|
2420
Capri Holdings
CPRI
$1.77B
| $1.24M | ﹤0.01% |
50,851
+46,309
| +1,020% | +$1.07M |
|
2421
Banco Macro
BMA
$5.7B
| $1.24M | ﹤0.01% |
13,731
-20,883
| -60% | -$1.58M |
|
2422
CALL
Rapid7
RPD
$634M
| $1.23M | ﹤0.01% |
81,200
+25,700
| +46% | +$423K |
|
2423
CALL
Glacier Bancorp
GBCI
$6.55B
| $1.23M | ﹤0.01% |
28,000
+27,400
| +4,567% | +$1.2M |
|
2424
CALL
Williams-Sonoma
WSM
$26.7B
| $1.23M | ﹤0.01% |
6,900
-1,500
| -18% | -$281K |
|
2425
Immunovant
IMVT
$8.09B
| $1.23M | ﹤0.01% |
48,411
+33,479
| +224% | +$747K |
|
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.