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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
1351
PUT
ACM Research
ACMR
$5.18B
| $4.52M | ﹤0.01% |
114,500
-9,300
| -8% | -$347K |
|
1352
PUT
Grayscale Bitcoin Trust
GBTC
$12B
| $4.51M | ﹤0.01% |
66,000
-800
| -1% | -$62.7K |
|
1353
PUT
Axsome Therapeutics
AXSM
$10.8B
| $4.51M | ﹤0.01% |
24,700
+2,600
| +12% | +$363K |
|
1354
CALL
T. Rowe Price
TROW
$23.4B
| $4.5M | ﹤0.01% |
44,000
+3,100
| +8% | +$320K |
|
1355
CALL
J.M. Smucker
SJM
$13.5B
| $4.5M | ﹤0.01% |
46,000
+11,900
| +35% | +$1.23M |
|
1356
CALL
Magnite
MGNI
$3.46B
| $4.5M | ﹤0.01% |
277,100
-89,000
| -24% | -$1.48M |
|
1357
CALL
Albertsons Companies
ACI
$6.09B
| $4.49M | ﹤0.01% |
261,600
+2,100
| +0.8% | +$37.4K |
|
1358
CALL
Green Plains
GPRE
$1.08B
| $4.48M | ﹤0.01% |
457,200
+219,900
| +93% | +$2.21M |
|
|
NNE
1359
CALL
Nano Nuclear Energy
NNE
$952M
| $4.48M | ﹤0.01% |
186,500
+33,400
| +22% | +$1.28M |
|
1360
CALL
Ionis Pharmaceuticals
IONS
$9.65B
| $4.48M | ﹤0.01% |
56,600
-17,100
| -23% | -$1.29M |
|
1361
PUT
AngloGold Ashanti
AU
$55.2B
| $4.48M | ﹤0.01% |
52,500
-124,600
| -70% | -$9.72M |
|
|
ETHW
1362
CALL
Bitwise Ethereum ETF
ETHW
$261M
| $4.47M | ﹤0.01% |
210,200
+172,500
| +458% | +$4.27M |
|
1363
PUT
Paychex
PAYX
$43.3B
| $4.46M | ﹤0.01% |
39,800
-60,400
| -60% | -$7.07M |
|
1364
PUT
LyondellBasell Industries
LYB
$20.5B
| $4.46M | ﹤0.01% |
103,000
-64,500
| -39% | -$2.92M |
|
1365
State Street SPDR S&P Metals & Mining ETF
XME
$4.86B
| $4.46M | ﹤0.01% |
+43,012
| New | +$4.25M |
|
|
FRMI
1366
PUT
Fermi Inc
FRMI
$3.28B
| $4.45M | ﹤0.01% |
+556,700
| New | +$10.9M |
|
1367
CALL
Sprouts Farmers Market
SFM
$7.59B
| $4.45M | ﹤0.01% |
55,800
+40,500
| +265% | +$3.63M |
|
1368
State Street Health Care Select Sector SPDR ETF
XLV
$44.6B
| $4.44M | ﹤0.01% |
28,657
-466,299
| -94% | -$69.8M |
|
1369
CALL
Red Cat Holdings
RCAT
$1.28B
| $4.43M | ﹤0.01% |
559,000
-141,400
| -20% | -$1.35M |
|
1370
CALL
Eldorado Gold
EGO
$11.2B
| $4.43M | ﹤0.01% |
123,300
+26,700
| +28% | +$799K |
|
1371
PUT
abrdn Physical Silver Shares ETF
SIVR
$4.48B
| $4.42M | ﹤0.01% |
65,400
+57,000
| +679% | +$3M |
|
1372
PUT
Mobileye
MBLY
$7.28B
| $4.41M | ﹤0.01% |
422,300
-125,300
| -23% | -$1.56M |
|
1373
CALL
CF Industries
CF
$20.2B
| $4.41M | ﹤0.01% |
57,000
-9,200
| -14% | -$756K |
|
1374
Akamai
AKAM
$15.1B
| $4.4M | ﹤0.01% |
50,476
+46,161
| +1,070% | +$3.8M |
|
1375
CALL
AMC Entertainment Holdings
AMC
$2.37B
| $4.4M | ﹤0.01% |
2,822,900
-475,400
| -14% | -$1.13M |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.