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 | |
|---|---|---|---|---|---|---|
6176
PUT
Cytek Biosciences
CTKB
$545M
| $27.8K | ﹤0.01% |
5,500
+4,700
| +588% | +$21.8K |
|
|
RBLY
6177
YieldMax RBLX Option Income Strategy ETF
RBLY
$2.22M
| $27.7K | ﹤0.01% |
+950
| New | +$37.3K |
|
6178
Teekay Tankers
TNK
$2.75B
| $27.7K | ﹤0.01% |
519
-2,019
| -80% | -$113K |
|
6179
ArcBest
ARCB
$3.23B
| $27.7K | ﹤0.01% |
373
-148
| -28% | -$10.5K |
|
6180
Artisan Partners
APAM
$2.79B
| $27.6K | ﹤0.01% |
678
-557
| -45% | -$23.8K |
|
6181
Diana Shipping
DSX
$302M
| $27.6K | ﹤0.01% |
16,856
-21,968
| -57% | -$38.2K |
|
6182
ESCO Technologies
ESE
$8.17B
| $27.5K | ﹤0.01% |
141
-114
| -45% | -$24K |
|
6183
PUT
Sinclair Inc
SBGI
$992M
| $27.5K | ﹤0.01% |
1,800
-99,100
| -98% | -$1.47M |
|
6184
PUT
SkinHealth Systems
SKIN
$88.8M
| $27.5K | ﹤0.01% |
+19,800
| New | +$28.6K |
|
|
ATXS
6185
PUT
DELISTED
Astria Therapeutics
ATXS
| $27.5K | ﹤0.01% |
+2,100
| New | +$25.1K |
|
|
HYFT
6186
CALL
MindWalk Holdings
HYFT
$60.6M
| $27.5K | ﹤0.01% |
15,100
-56,800
| -79% | -$100K |
|
6187
CALL
Commerce Bancshares
CBSH
$8.53B
| $27.5K | ﹤0.01% |
525
-105
| -17% | -$5.49K |
|
6188
Tenaya Therapeutics
TNYA
$161M
| $27.4K | ﹤0.01% |
38,543
-73,389
| -66% | -$99.8K |
|
|
ACH
6189
CALL
Accendra Health
ACH
$237M
| $27.4K | ﹤0.01% |
9,800
-17,700
| -64% | -$63.3K |
|
6190
PUT
Teradata
TDC
$2.92B
| $27.4K | ﹤0.01% |
900
-700
| -44% | -$18.3K |
|
6191
PUT
Dream Finders Homes
DFH
$1.16B
| $27.4K | ﹤0.01% |
1,600
-2,800
| -64% | -$57.3K |
|
6192
CALL
Select Water Solutions
WTTR
$2.3B
| $27.4K | ﹤0.01% |
2,600
-600
| -19% | -$6.47K |
|
6193
PUT
Embecta
EMBC
$216M
| $27.3K | ﹤0.01% |
2,300
-4,600
| -67% | -$60.7K |
|
|
COIW
6194
Roundhill COIN WeeklyPay ETF
COIW
$31.3M
| $27.3K | ﹤0.01% |
+1,374
| New | +$42.9K |
|
6195
PUT
Evolution Petroleum
EPM
$132M
| $27.3K | ﹤0.01% |
7,700
| – | – |
|
6196
CALL
Radiant Logistics
RLGT
$386M
| $27.2K | ﹤0.01% |
4,300
-8,100
| -65% | -$50.3K |
|
6197
Gladstone Capital
GLAD
$422M
| $27.2K | ﹤0.01% |
1,317
-1,125
| -46% | -$22.8K |
|
6198
CALL
Teekay
TK
$1.01B
| $27.1K | ﹤0.01% |
3,000
-1,200
| -29% | -$11K |
|
6199
CALL
Procure Space ETF
UFO
$612M
| $27.1K | ﹤0.01% |
+700
| New | +$25.6K |
|
6200
Hain Celestial
HAIN
$45M
| $27K | ﹤0.01% |
25,244
+14,548
| +136% | +$17.9K |
|
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.