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 | |
|---|---|---|---|---|---|---|
4501
PUT
Enovis
ENOV
$1.74B
| $155K | ﹤0.01% |
5,800
-1,300
| -18% | -$38.4K |
|
4502
CALL
Bain Capital Specialty
BCSF
$821M
| $154K | ﹤0.01% |
11,100
+300
| +3% | +$4.21K |
|
4503
Gain Therapeutics
GANX
$72.1M
| $154K | ﹤0.01% |
+47,946
| New | +$128K |
|
|
RPTX
4504
CALL
DELISTED
Repare Therapeutics
RPTX
| $154K | ﹤0.01% |
59,300
-5,000
| -8% | -$10.1K |
|
|
GES
4505
PUT
DELISTED
Guess Inc
GES
| $154K | ﹤0.01% |
9,200
-70,300
| -88% | -$1.19M |
|
4506
CALL
Relmada Therapeutics
RLMD
$540M
| $154K | ﹤0.01% |
+31,900
| New | +$107K |
|
4507
CALL
Adecoagro
AGRO
$1.4B
| $154K | ﹤0.01% |
+19,400
| New | +$152K |
|
4508
PUT
Direxion Daily MSCI Emerging Markets Bear 3X ETF
EDZ
$21.5M
| $154K | ﹤0.01% |
7,300
+300
| +4% | +$11.3K |
|
|
GOLD
4509
PUT
Gold.com Inc
GOLD
$1.16B
| $153K | ﹤0.01% |
4,500
+1,700
| +61% | +$48.6K |
|
4510
Iridium Communications
IRDM
$4.7B
| $153K | ﹤0.01% |
8,787
-6,729
| -43% | -$119K |
|
4511
PUT
Ring Energy
REI
$307M
| $153K | ﹤0.01% |
175,500
-5,200
| -3% | -$4.96K |
|
4512
Bruker
BRKR
$9.4B
| $152K | ﹤0.01% |
3,236
-10,411
| -76% | -$440K |
|
4513
Atlanta Braves Holdings Series B
BATRK
$3.28B
| $152K | ﹤0.01% |
3,863
-898
| -19% | -$35.5K |
|
|
STKE
4514
CALL
Sol Strategies Inc
STKE
$38.8M
| $152K | ﹤0.01% |
99,500
+90,500
| +1,006% | +$262K |
|
|
MTA
4515
Metalla Royalty & Streaming
MTA
$689M
| $152K | ﹤0.01% |
19,555
-25,381
| -56% | -$183K |
|
4516
CALL
Nabors Industries
NBR
$1.17B
| $152K | ﹤0.01% |
2,800
+400
| +17% | +$19.5K |
|
4517
Genpact
G
$6.22B
| $152K | ﹤0.01% |
+3,248
| New | +$140K |
|
4518
Dine Brands
DIN
$462M
| $152K | ﹤0.01% |
4,716
-26,378
| -85% | -$766K |
|
4519
CALL
AMES National
ATLO
$271M
| $152K | ﹤0.01% |
6,600
-19,800
| -75% | -$426K |
|
4520
PNC Financial Services
PNC
$99.1B
| $151K | ﹤0.01% |
724
-5,897
| -89% | -$1.14M |
|
4521
CALL
Tecnoglass
TGLS
$1.99B
| $151K | ﹤0.01% |
3,000
-1,500
| -33% | -$81.9K |
|
4522
PagSeguro Digital
PAGS
$2.67B
| $151K | ﹤0.01% |
+15,638
| New | +$150K |
|
|
AHRT
4523
AH Realty Trust
AHRT
$536M
| $151K | ﹤0.01% |
+22,743
| New | +$150K |
|
|
NBP
4524
PUT
NovaBridge Biosciences American Depositary Shares
NBP
$186M
| $150K | ﹤0.01% |
37,800
+100
| +0.3% | +$443 |
|
4525
CALL
Aemetis
AMTX
$99.2M
| $150K | ﹤0.01% |
108,100
+48,600
| +82% | +$97.8K |
|
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.