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 | |
|---|---|---|---|---|---|---|
2201
PUT
Valley National Bancorp
VLY
$7.93B
| $1.53M | ﹤0.01% |
131,300
+34,900
| +36% | +$387K |
|
2202
PUT
Prothena Corp
PRTA
$458M
| $1.53M | ﹤0.01% |
160,300
-104,900
| -40% | -$1.07M |
|
2203
CALL
Flex
FLEX
$43.4B
| $1.53M | ﹤0.01% |
25,300
-8,600
| -25% | -$531K |
|
|
XRN
2204
PUT
Chiron Real Estate Inc
XRN
$544M
| $1.53M | ﹤0.01% |
45,300
-3,100
| -6% | -$101K |
|
2205
PUT
Globus Medical
GMED
$10.4B
| $1.53M | ﹤0.01% |
17,500
+17,400
| +17,400% | +$1.32M |
|
2206
CALL
Aquestive Therapeutics
AQST
$462M
| $1.53M | ﹤0.01% |
236,300
+27,300
| +13% | +$170K |
|
2207
PUT
Sportradar
SRAD
$4.23B
| $1.53M | ﹤0.01% |
64,200
+36,400
| +131% | +$875K |
|
2208
PUT
Jefferies Financial Group
JEF
$12.9B
| $1.52M | ﹤0.01% |
24,600
-2,400
| -9% | -$138K |
|
2209
CALL
Keysight
KEYS
$54.5B
| $1.52M | ﹤0.01% |
7,500
-16,900
| -69% | -$3.14M |
|
2210
Grindr
GRND
$2.64B
| $1.52M | ﹤0.01% |
+112,448
| New | +$1.53M |
|
2211
PUT
DaVita
DVA
$15.1B
| $1.52M | ﹤0.01% |
13,400
+900
| +7% | +$109K |
|
2212
CALL
Lamar Advertising Co
LAMR
$16.2B
| $1.52M | ﹤0.01% |
12,000
+7,300
| +155% | +$914K |
|
2213
Crescent Energy
CRGY
$3.72B
| $1.52M | ﹤0.01% |
180,898
+121,832
| +206% | +$1.07M |
|
2214
PUT
RUM Group Inc
RUM
$1.57B
| $1.52M | ﹤0.01% |
240,100
-204,800
| -46% | -$1.4M |
|
2215
PUT
Rockwell Automation
ROK
$51.4B
| $1.52M | ﹤0.01% |
3,900
+800
| +26% | +$301K |
|
2216
CALL
Kodak
KODK
$806M
| $1.52M | ﹤0.01% |
179,300
-101,400
| -36% | -$758K |
|
2217
PUT
Viatris
VTRS
$20.1B
| $1.52M | ﹤0.01% |
121,800
-110,700
| -48% | -$1.19M |
|
2218
CALL
Travel + Leisure Co
TNL
$4.54B
| $1.52M | ﹤0.01% |
21,500
+17,600
| +451% | +$1.15M |
|
2219
PUT
Clear Secure
YOU
$5.26B
| $1.52M | ﹤0.01% |
43,200
+26,400
| +157% | +$899K |
|
2220
CALL
Asana
ASAN
$1.58B
| $1.51M | ﹤0.01% |
110,100
-28,100
| -20% | -$386K |
|
2221
CALL
Markel Group
MKL
$25B
| $1.5M | ﹤0.01% |
700
+600
| +600% | +$1.22M |
|
|
NGD
2222
DELISTED
New Gold Inc
NGD
| $1.5M | ﹤0.01% |
+172,761
| New | +$1.3M |
|
2223
PUT
NextNav
NN
$1.7B
| $1.5M | ﹤0.01% |
90,400
+28,900
| +47% | +$410K |
|
|
TLN
2224
Talen Energy Corp
TLN
$17.2B
| $1.5M | ﹤0.01% |
+4,011
| New | +$1.56M |
|
2225
PUT
Kyndryl
KD
$2.66B
| $1.5M | ﹤0.01% |
56,600
+26,800
| +90% | +$727K |
|
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.