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 | |
|---|---|---|---|---|---|---|
4026
Playboy Inc
PLBY
$138M
| $244K | ﹤0.01% |
129,585
+78,474
| +154% | +$128K |
|
4027
CALL
UroGen Pharma
URGN
$1.99B
| $244K | ﹤0.01% |
10,400
-84,700
| -89% | -$1.84M |
|
4028
Janux Therapeutics
JANX
$920M
| $242K | ﹤0.01% |
17,567
+13,971
| +389% | +$329K |
|
4029
CALL
Loews
L
$24.6B
| $242K | ﹤0.01% |
2,300
+1,000
| +77% | +$103K |
|
4030
Power Integrations
POWI
$3.23B
| $242K | ﹤0.01% |
6,812
+6,760
| +13,000% | +$256K |
|
4031
Portland General Electric
POR
$5.85B
| $242K | ﹤0.01% |
+5,041
| New | +$238K |
|
4032
Karyopharm Therapeutics
KPTI
$157M
| $242K | ﹤0.01% |
32,868
+27,006
| +461% | +$165K |
|
4033
ProShares VIX Mid-Term Futures ETF
VIXM
$55.9M
| $242K | ﹤0.01% |
15,837
+10,635
| +204% | +$170K |
|
4034
CALL
World Kinect Corp
WKC
$2.06B
| $241K | ﹤0.01% |
+10,300
| New | +$254K |
|
4035
PUT
Mueller Industries
MLI
$14.5B
| $241K | ﹤0.01% |
4,200
+400
| +11% | +$21.5K |
|
4036
DXC Technology
DXC
$1.91B
| $241K | ﹤0.01% |
16,442
+6,872
| +72% | +$94.5K |
|
|
TGB
4037
PUT
Trekor Metals
TGB
$2.51B
| $241K | ﹤0.01% |
42,500
-1,400
| -3% | -$6.59K |
|
4038
PUT
Sonoco
SON
$5.82B
| $240K | ﹤0.01% |
5,500
-7,200
| -57% | -$298K |
|
4039
PUT
Sally Beauty Holdings
SBH
$1.48B
| $240K | ﹤0.01% |
16,800
-9,800
| -37% | -$148K |
|
4040
CALL
Manulife Financial
MFC
$73.7B
| $239K | ﹤0.01% |
6,600
-9,300
| -58% | -$316K |
|
4041
CALL
Jacobs Solutions
J
$16.3B
| $238K | ﹤0.01% |
1,800
-6,800
| -79% | -$997K |
|
|
UROY
4042
Uranium Royalty Corp
UROY
$502M
| $238K | ﹤0.01% |
67,345
-110,624
| -62% | -$433K |
|
4043
CALL
Gates Industrial Corporation Ltd.
GTES
$6.37B
| $238K | ﹤0.01% |
11,100
+9,600
| +640% | +$222K |
|
4044
James Hardie Industries
JHX
$15.4B
| $238K | ﹤0.01% |
+11,484
| New | +$230K |
|
|
CONI
4045
GraniteShares 2x Short COIN Daily ETF
CONI
$10.9M
| $238K | ﹤0.01% |
3,491
-755
| -18% | -$35.7K |
|
4046
PUT
Open Text
OTEX
$6.38B
| $238K | ﹤0.01% |
7,300
-900
| -11% | -$32.1K |
|
4047
CALL
HDFC Bank
HDB
$123B
| $238K | ﹤0.01% |
9,000
-5,000
| -36% | -$180K |
|
4048
Honda
HMC
$40.2B
| $237K | ﹤0.01% |
+8,053
| New | +$244K |
|
4049
United States Antimony
UAMY
$744M
| $237K | ﹤0.01% |
47,138
-194,321
| -80% | -$1.53M |
|
4050
PUT
Qorvo
QRVO
$8.05B
| $237K | ﹤0.01% |
2,800
-2,300
| -45% | -$203K |
|
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.