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 | |
|---|---|---|---|---|---|---|
4451
AlTi Global
ALTI
$395M
| $162K | ﹤0.01% |
34,860
+32,697
| +1,512% | +$135K |
|
4452
Valero Energy
VLO
$89.5B
| $161K | ﹤0.01% |
+991
| New | +$168K |
|
4453
PUT
PagerDuty
PD
$830M
| $161K | ﹤0.01% |
12,300
-189,300
| -94% | -$2.76M |
|
4454
Metallus
MTUS
$833M
| $161K | ﹤0.01% |
9,394
+9,389
| +187,780% | +$161K |
|
4455
CALL
MBIA
MBI
$275M
| $161K | ﹤0.01% |
22,500
+11,600
| +106% | +$83.8K |
|
4456
PUT
USA Compression Partners
USAC
$3.69B
| $161K | ﹤0.01% |
7,000
+200
| +3% | +$4.69K |
|
|
BTFX
4457
PUT
DELISTED
Valkyrie ETF Trust II CoinShares Bitcoin Leverage ETF
BTFX
| $161K | ﹤0.01% |
4,200
-52,300
| -93% | -$2.3M |
|
4458
Lazard
LAZ
$3.96B
| $161K | ﹤0.01% |
+3,307
| New | +$165K |
|
|
AL
4459
PUT
DELISTED
Air Lease Corp
AL
| $161K | ﹤0.01% |
2,500
-6,900
| -73% | -$441K |
|
4460
PUT
PubMatic
PUBM
$608M
| $161K | ﹤0.01% |
18,100
-1,800
| -9% | -$15.7K |
|
4461
CALL
Alto Neuroscience
ANRO
$1.04B
| $160K | ﹤0.01% |
9,000
+1,200
| +15% | +$15.1K |
|
4462
PUT
3D Systems Corp
DDD
$405M
| $160K | ﹤0.01% |
90,500
-47,500
| -34% | -$116K |
|
4463
CALL
FLEX LNG
FLNG
$1.69B
| $160K | ﹤0.01% |
6,400
-8,500
| -57% | -$217K |
|
4464
CALL
Veralto
VLTO
$24.1B
| $160K | ﹤0.01% |
1,600
+1,500
| +1,500% | +$152K |
|
4465
PUT
The Joint Corp
JYNT
$119M
| $160K | ﹤0.01% |
18,300
-2,200
| -11% | -$18.7K |
|
4466
Methanex
MEOH
$4.23B
| $159K | ﹤0.01% |
4,011
-35,362
| -90% | -$1.32M |
|
4467
ProShares UltraShort S&P500
SDS
$435M
| $159K | ﹤0.01% |
+2,326
| New | +$164K |
|
4468
AllianceBernstein
AB
$3.47B
| $159K | ﹤0.01% |
4,133
-7,931
| -66% | -$314K |
|
4469
CALL
Grupo Cibest SA
CIB
$21.2B
| $159K | ﹤0.01% |
2,500
+2,000
| +400% | +$120K |
|
4470
Kingstone Companies
KINS
$295M
| $159K | ﹤0.01% |
+9,448
| New | +$144K |
|
|
SEZL
4471
PUT
Sezzle
SEZL
$5.13B
| $159K | ﹤0.01% |
2,500
-22,300
| -90% | -$1.52M |
|
4472
PUT
Immix Biopharma
IMMX
$582M
| $158K | ﹤0.01% |
+30,300
| New | +$125K |
|
4473
CALL
Vaalco Energy
EGY
$562M
| $158K | ﹤0.01% |
43,400
-28,100
| -39% | -$104K |
|
4474
Ferguson
FERG
$43.9B
| $157K | ﹤0.01% |
707
-1,724
| -71% | -$412K |
|
4475
PUT
AAR Corp
AIR
$5.4B
| $157K | ﹤0.01% |
1,900
-21,900
| -92% | -$1.81M |
|
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.