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 | |
|---|---|---|---|---|---|---|
|
BLSH
2076
PUT
Bullish
BLSH
$3.63B
| $1.8M | ﹤0.01% |
47,400
-251,100
| -84% | -$12.2M |
|
2077
PUT
M&T Bank
MTB
$36.2B
| $1.79M | ﹤0.01% |
8,900
+500
| +6% | +$95.5K |
|
|
SOLS
2078
CALL
Solstice Advanced Materials
SOLS
$9.62B
| $1.79M | ﹤0.01% |
+36,900
| New | +$1.74M |
|
2079
PUT
Gartner
IT
$9.41B
| $1.79M | ﹤0.01% |
7,100
-9,600
| -57% | -$2.31M |
|
2080
State Street SPDR S&P Homebuilders ETF
XHB
$1.74B
| $1.79M | ﹤0.01% |
17,381
-39,041
| -69% | -$4.15M |
|
2081
Apollo Global Management
APO
$70.7B
| $1.79M | ﹤0.01% |
+12,362
| New | +$1.64M |
|
2082
PUT
Neurocrine Biosciences
NBIX
$17.7B
| $1.79M | ﹤0.01% |
12,600
+6,400
| +103% | +$927K |
|
2083
CALL
Birkenstock
BIRK
$7.47B
| $1.78M | ﹤0.01% |
43,600
+20,600
| +90% | +$872K |
|
2084
CALL
Ormat Technologies
ORA
$6.11B
| $1.78M | ﹤0.01% |
16,100
+11,100
| +222% | +$1.21M |
|
2085
PUT
Red Cat Holdings
RCAT
$1.16B
| $1.77M | ﹤0.01% |
223,600
-129,800
| -37% | -$1.24M |
|
2086
McEwen Inc
MUX
$1.03B
| $1.77M | ﹤0.01% |
+95,689
| New | +$1.78M |
|
2087
PUT
US Foods
USFD
$21.4B
| $1.77M | ﹤0.01% |
23,500
+12,700
| +118% | +$954K |
|
2088
CALL
Shake Shack
SHAK
$2.3B
| $1.77M | ﹤0.01% |
21,800
-2,000
| -8% | -$176K |
|
2089
PUT
Dropbox
DBX
$6.81B
| $1.76M | ﹤0.01% |
63,200
-50,200
| -44% | -$1.46M |
|
|
ARR
2090
Armour Residential REIT
ARR
$2.02B
| $1.75M | ﹤0.01% |
99,057
-102,345
| -51% | -$1.7M |
|
2091
ProShares Ultra Bloomberg Natural Gas
BOIL
$417M
| $1.75M | ﹤0.01% |
38,114
+36,459
| +2,203% | +$2.23M |
|
2092
TKO Group
TKO
$13.5B
| $1.74M | ﹤0.01% |
8,347
-6,406
| -43% | -$1.24M |
|
2093
CALL
Harmony Gold Mining
HMY
$9.92B
| $1.74M | ﹤0.01% |
87,600
-104,400
| -54% | -$1.95M |
|
|
2094
CALL
Dropbox
DBX
$6.81B
| $1.74M | ﹤0.01% |
62,700
-66,200
| -51% | -$1.93M |
|
2095
PUT
SL Green Realty
SLG
$3.88B
| $1.74M | ﹤0.01% |
38,000
-4,600
| -11% | -$227K |
|
2096
PUT
Vicor
VICR
$9.62B
| $1.74M | ﹤0.01% |
15,900
+11,100
| +231% | +$944K |
|
2097
ReNew
RNW
$2.24B
| $1.74M | ﹤0.01% |
307,838
+180,059
| +141% | +$1.3M |
|
2098
Richtech Robotics
RR
$347M
| $1.74M | ﹤0.01% |
537,317
+264,253
| +97% | +$1.17M |
|
2099
CALL
NetEase
NTES
$76.5B
| $1.73M | ﹤0.01% |
12,600
-4,900
| -28% | -$696K |
|
2100
PUT
Restaurant Brands International
QSR
$25.1B
| $1.73M | ﹤0.01% |
25,400
-6,500
| -20% | -$448K |
|
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.