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 | |
|---|---|---|---|---|---|---|
3176
PUT
Ligand Pharmaceuticals
LGND
$5.96B
| $567K | ﹤0.01% |
+3,000
| New | +$576K |
|
3177
CALL
Indivior Pharmaceuticals
INDV
$4.73B
| $567K | ﹤0.01% |
15,800
-147,500
| -90% | -$4.5M |
|
|
CNR
3178
CALL
Core Natural Resources Inc
CNR
$4.16B
| $566K | ﹤0.01% |
6,400
-23,900
| -79% | -$2.04M |
|
|
OPRA
3179
CALL
Opera Ltd
OPRA
$1.69B
| $566K | ﹤0.01% |
40,000
-95,300
| -70% | -$1.41M |
|
3180
PUT
Commault Systems
CVLT
$6.19B
| $564K | ﹤0.01% |
4,500
+2,000
| +80% | +$281K |
|
3181
PUT
Cars.com
CARS
$660M
| $564K | ﹤0.01% |
46,200
-31,100
| -40% | -$362K |
|
|
GLDB
3182
CALL
IDX Alternative FIAT ETF
GLDB
$34.3M
| $563K | ﹤0.01% |
+114,500
| New | +$2.73M |
|
|
DQ
3183
PUT
Daqo New Energy
DQ
$815M
| $563K | ﹤0.01% |
19,100
-71,700
| -79% | -$2.19M |
|
3184
CALL
Theravance Biopharma
TBPH
$874M
| $563K | ﹤0.01% |
30,100
+500
| +2% | +$8.29K |
|
3185
CALL
ProPetro Holding
PUMP
$1.32B
| $563K | ﹤0.01% |
59,200
+56,700
| +2,268% | +$493K |
|
3186
CALL
Sonoco
SON
$5.8B
| $563K | ﹤0.01% |
12,900
+1,700
| +15% | +$70.4K |
|
3187
CALL
Contango Silver & Gold Inc
CTGO
$550M
| $563K | ﹤0.01% |
21,300
-7,400
| -26% | -$181K |
|
3188
PUT
Raymond James Financial
RJF
$33.3B
| $562K | ﹤0.01% |
3,500
-26,000
| -88% | -$4.2M |
|
3189
CALL
Bentley Systems
BSY
$10.2B
| $561K | ﹤0.01% |
14,700
-19,000
| -56% | -$866K |
|
3190
Quince Therapeutics
QNCX
$17.5M
| $560K | ﹤0.01% |
836
+393
| +89% | +$198K |
|
3191
PUT
Aurinia Pharmaceuticals
AUPH
$1.96B
| $560K | ﹤0.01% |
35,100
-3,200
| -8% | -$45.4K |
|
3192
nLIGHT
LASR
$3.82B
| $559K | ﹤0.01% |
14,915
+7,836
| +111% | +$262K |
|
3193
CALL
Lantheus
LNTH
$7.03B
| $559K | ﹤0.01% |
8,400
-8,600
| -51% | -$500K |
|
3194
Darling Ingredients
DAR
$9.62B
| $558K | ﹤0.01% |
15,505
-30,809
| -67% | -$1.04M |
|
3195
CALL
Vail Resorts
MTN
$5.28B
| $558K | ﹤0.01% |
4,200
-16,600
| -80% | -$2.44M |
|
|
ACB
3196
CALL
Aurora Cannabis
ACB
$170M
| $558K | ﹤0.01% |
133,400
+65,600
| +97% | +$321K |
|
3197
CALL
Idaho Strategic Resources
IDR
$458M
| $556K | ﹤0.01% |
13,800
-22,300
| -62% | -$852K |
|
|
CGC
3198
Canopy Growth
CGC
$390M
| $556K | ﹤0.01% |
+487,670
| New | +$627K |
|
3199
CALL
Cincinnati Financial
CINF
$28.5B
| $555K | ﹤0.01% |
3,400
+2,800
| +467% | +$454K |
|
|
Q
3200
PUT
Qnity Electronics Inc
Q
$27.8B
| $555K | ﹤0.01% |
+6,800
| New | +$578K |
|
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.