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 | |
|---|---|---|---|---|---|---|
2151
PUT
Pebblebrook Hotel Trust
PEB
$2.16B
| $1.62M | ﹤0.01% |
143,500
| – | – |
|
2152
Teladoc Health
TDOC
$1.58B
| $1.62M | ﹤0.01% |
231,680
-229,727
| -50% | -$1.8M |
|
|
DX
2153
Dynex Capital
DX
$2.99B
| $1.62M | ﹤0.01% |
115,448
+41,974
| +57% | +$567K |
|
2154
CALL
Alight
ALIT
$497M
| $1.62M | ﹤0.01% |
41,435
+12,435
| +43% | +$619K |
|
2155
CALL
M&T Bank
MTB
$36.2B
| $1.61M | ﹤0.01% |
8,000
-1,700
| -18% | -$325K |
|
|
CNR
2156
PUT
Core Natural Resources Inc
CNR
$4.19B
| $1.61M | ﹤0.01% |
18,200
-18,900
| -51% | -$1.61M |
|
2157
CALL
Nuvation Bio
NUVB
$2.24B
| $1.61M | ﹤0.01% |
179,700
+145,500
| +425% | +$901K |
|
2158
CALL
indie Semiconductor
INDI
$733M
| $1.61M | ﹤0.01% |
455,700
-284,500
| -38% | -$1.25M |
|
2159
CALL
F5
FFIV
$22.1B
| $1.61M | ﹤0.01% |
6,300
-400
| -6% | -$108K |
|
2160
PUT
Match Group
MTCH
$8.84B
| $1.61M | ﹤0.01% |
49,800
-78,900
| -61% | -$2.59M |
|
2161
Capricor Therapeutics
CAPR
$1.14B
| $1.61M | ﹤0.01% |
+55,707
| New | +$728K |
|
2162
PIMCO 25+ Year Zero Coupon US Treasury Index Exchange-Traded Fund
ZROZ
$1.34B
| $1.61M | ﹤0.01% |
25,017
+2,912
| +13% | +$197K |
|
|
HIMX
2163
CALL
Himax Technologies
HIMX
$2.2B
| $1.61M | ﹤0.01% |
196,000
-8,000
| -4% | -$67.7K |
|
2164
CALL
XPO
XPO
$25B
| $1.6M | ﹤0.01% |
11,800
-6,400
| -35% | -$872K |
|
2165
CALL
UL Solutions
ULS
$17.2B
| $1.6M | ﹤0.01% |
20,300
-21,800
| -52% | -$1.75M |
|
2166
PUT
Huntington Bancshares
HBAN
$35.1B
| $1.6M | ﹤0.01% |
92,200
-23,000
| -20% | -$377K |
|
2167
United States Natural Gas Fund
UNG
$470M
| $1.6M | ﹤0.01% |
130,271
-44,253
| -25% | -$596K |
|
2168
PUT
Unum
UNM
$13.8B
| $1.6M | ﹤0.01% |
20,600
+10,800
| +110% | +$826K |
|
2169
CALL
Weibo
WB
$1.9B
| $1.6M | ﹤0.01% |
156,100
+22,400
| +17% | +$240K |
|
2170
Vertex Pharmaceuticals
VRTX
$121B
| $1.59M | ﹤0.01% |
3,511
+1,908
| +119% | +$822K |
|
2171
Roblox
RBLX
$34B
| $1.59M | ﹤0.01% |
19,633
-12,750
| -39% | -$1.35M |
|
2172
PUT
H&R Block
HRB
$5.18B
| $1.59M | ﹤0.01% |
36,500
-2,500
| -6% | -$117K |
|
|
EMBJ
2173
CALL
Embraer S.A. ADS
EMBJ
$11.6B
| $1.59M | ﹤0.01% |
24,700
-59,400
| -71% | -$3.72M |
|
2174
VanEck Uranium + Nuclear Energy ETF
NLR
$3.89B
| $1.59M | ﹤0.01% |
12,769
+2,942
| +30% | +$405K |
|
2175
PUT
ASP Isotopes
ASPI
$487M
| $1.59M | ﹤0.01% |
296,400
-92,100
| -24% | -$733K |
|
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.