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 | |
|---|---|---|---|---|---|---|
|
NLOP
4076
PUT
Net Lease Office Properties
NLOP
$175M
| $232K | ﹤0.01% |
9,000
+7,000
| +350% | +$198K |
|
|
BZUN
4077
PUT
Baozun
BZUN
$179M
| $232K | ﹤0.01% |
87,200
+86,300
| +9,589% | +$271K |
|
4078
PUT
TechnipFMC
FTI
$28.6B
| $232K | ﹤0.01% |
5,200
-7,400
| -59% | -$312K |
|
|
JAMF
4079
CALL
DELISTED
Jamf
JAMF
| $232K | ﹤0.01% |
17,800
+16,200
| +1,013% | +$197K |
|
4080
PUT
Barnes & Noble Education
BNED
$433M
| $231K | ﹤0.01% |
25,100
+6,500
| +35% | +$57.3K |
|
|
TTAN
4081
ServiceTitan Inc
TTAN
$8.1B
| $230K | ﹤0.01% |
2,159
-1,731
| -44% | -$169K |
|
|
TGEN
4082
Tecogen Inc
TGEN
$88M
| $230K | ﹤0.01% |
46,531
+14,969
| +47% | +$112K |
|
4083
Vanguard Long-Term Treasury ETF
VGLT
$10.1B
| $230K | ﹤0.01% |
4,116
-10,697
| -72% | -$609K |
|
4084
CALL
MSCI
MSCI
$42.3B
| $229K | ﹤0.01% |
400
-2,400
| -86% | -$1.35M |
|
4085
PUT
ACI Worldwide
ACIW
$6.11B
| $229K | ﹤0.01% |
4,800
| – | – |
|
4086
CALL
Westlake Corp
WLK
$9.21B
| $229K | ﹤0.01% |
3,100
-18,400
| -86% | -$1.31M |
|
4087
CALL
Akebia Therapeutics
AKBA
$335M
| $229K | ﹤0.01% |
142,300
-4,100
| -3% | -$8.59K |
|
4088
Globe Life
GL
$13.9B
| $229K | ﹤0.01% |
+1,637
| New | +$222K |
|
4089
CALL
Leggett & Platt
LEG
$1.4B
| $229K | ﹤0.01% |
20,800
-40,400
| -66% | -$397K |
|
4090
PUT
Solid Power
SLDP
$450M
| $229K | ﹤0.01% |
53,800
-188,000
| -78% | -$1.04M |
|
|
PSIX
4091
CALL
Power Solutions International
PSIX
$588M
| $229K | ﹤0.01% |
4,000
+1,200
| +43% | +$85.7K |
|
4092
CALL
Masco
MAS
$14.7B
| $228K | ﹤0.01% |
3,600
-10,800
| -75% | -$701K |
|
4093
PUT
Aegon
AEG
$13.4B
| $228K | ﹤0.01% |
29,600
+100
| +0.3% | +$765 |
|
4094
Verisk Analytics
VRSK
$27.9B
| $228K | ﹤0.01% |
+1,019
| New | +$230K |
|
|
GEVX
4095
Tradr 2X Long GEV Daily ETF
GEVX
$28M
| $228K | ﹤0.01% |
22,056
+177
| +0.8% | +$1.69K |
|
4096
Schrodinger
SDGR
$1.12B
| $228K | ﹤0.01% |
12,727
-2,535
| -17% | -$48.1K |
|
|
PPIH
4097
Perma-Pipe International
PPIH
$193M
| $227K | ﹤0.01% |
7,489
+469
| +7% | +$12.9K |
|
4098
PUT
Cellebrite
CLBT
$3.78B
| $227K | ﹤0.01% |
12,600
+1,200
| +11% | +$21.5K |
|
|
VNET
4099
VNET Group
VNET
$1.78B
| $226K | ﹤0.01% |
+26,767
| New | +$248K |
|
|
DYNC
4100
CALL
Dynamix Corp
DYNC
$241M
| $226K | ﹤0.01% |
22,000
-28,500
| -56% | -$296K |
|
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.