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 | |
|---|---|---|---|---|---|---|
4551
CALL
Coty
COTY
$2.4B
| $148K | ﹤0.01% |
47,900
-163,200
| -77% | -$593K |
|
|
LIF
4552
CALL
Life360
LIF
$4.48B
| $148K | ﹤0.01% |
2,300
+1,400
| +156% | +$116K |
|
4553
CALL
Repligen
RGEN
$6.91B
| $147K | ﹤0.01% |
900
-700
| -44% | -$110K |
|
|
LFGY
4554
YieldMax Crypto Industry & Tech Portfolio Option Income ETF
LFGY
$86.2M
| $147K | ﹤0.01% |
5,910
+833
| +16% | +$26.2K |
|
4555
ProFrac Holding
ACDC
$653M
| $147K | ﹤0.01% |
37,868
+23,900
| +171% | +$97.6K |
|
4556
ProShares UltraShort Dow 30
DXD
$43.6M
| $147K | ﹤0.01% |
7,173
+1,112
| +18% | +$23.7K |
|
|
LB
4557
CALL
LandBridge Co
LB
$2.09B
| $147K | ﹤0.01% |
3,000
+100
| +3% | +$5.82K |
|
4558
ChargePoint
CHPT
$134M
| $147K | ﹤0.01% |
22,128
+6,006
| +37% | +$56.8K |
|
4559
PUT
SFL Corp
SFL
$1.61B
| $147K | ﹤0.01% |
18,800
+3,000
| +19% | +$23K |
|
4560
CryoPort
CYRX
$753M
| $147K | ﹤0.01% |
15,292
-17,508
| -53% | -$165K |
|
4561
Brunswick
BC
$5.23B
| $147K | ﹤0.01% |
1,976
-4,743
| -71% | -$321K |
|
4562
PUT
Artisan Partners
APAM
$2.86B
| $147K | ﹤0.01% |
3,600
+3,400
| +1,700% | +$145K |
|
4563
Ventas
VTR
$47.5B
| $147K | ﹤0.01% |
1,895
-6,935
| -79% | -$523K |
|
|
BZUN
4564
CALL
Baozun
BZUN
$179M
| $147K | ﹤0.01% |
55,100
+53,800
| +4,138% | +$169K |
|
4565
Upexi
UPXI
$58.3M
| $147K | ﹤0.01% |
87,203
-179,932
| -67% | -$679K |
|
4566
Westlake Corp
WLK
$9.26B
| $146K | ﹤0.01% |
+1,981
| New | +$141K |
|
4567
CALL
Gogo Inc
GOGO
$525M
| $146K | ﹤0.01% |
31,400
+24,400
| +349% | +$179K |
|
4568
Nucor
NUE
$58.3B
| $146K | ﹤0.01% |
+895
| New | +$134K |
|
4569
PUT
Perimeter Solutions
PRM
$5.66B
| $146K | ﹤0.01% |
5,300
+2,700
| +104% | +$68.2K |
|
4570
Kimbell Royalty Partners
KRP
$1.46B
| $146K | ﹤0.01% |
+12,400
| New | +$159K |
|
4571
PUT
Olin
OLN
$2.53B
| $146K | ﹤0.01% |
7,000
-700
| -9% | -$15.1K |
|
|
CSGS
4572
DELISTED
CSG Systems International
CSGS
| $146K | ﹤0.01% |
+1,901
| New | +$140K |
|
4573
PUT
VeriSign
VRSN
$26.3B
| $146K | ﹤0.01% |
600
+100
| +20% | +$25.1K |
|
4574
Teucrium Sugar Fund
CANE
$74M
| $146K | ﹤0.01% |
14,926
-2,054
| -12% | -$19.9K |
|
4575
PUT
AXT Inc
AXTI
$2.42B
| $146K | ﹤0.01% |
+8,900
| New | +$86K |
|
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.