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 | |
|---|---|---|---|---|---|---|
7951
CALL
Purple Innovation
PRPL
$41.7M
| $1.38K | ﹤0.01% |
80
-2,068
| -96% | -$41.3K |
|
|
OPEX
7952
Tradr 2X Long OPEN Daily ETF
OPEX
$8.29M
| $1.37K | ﹤0.01% |
+32
| New | +$2.3K |
|
7953
SurgePays
SURG
$7.27M
| $1.36K | ﹤0.01% |
812
-11,722
| -94% | -$26.1K |
|
|
CVAC
7954
CALL
DELISTED
CureVac
CVAC
| $1.35K | ﹤0.01% |
+300
| New | +$1.54K |
|
7955
ProShares UltraShort FTSE Europe
EPV
$10.1M
| $1.35K | ﹤0.01% |
62
-57
| -48% | -$1.35K |
|
7956
CALL
Escalade
ESCA
$311M
| $1.35K | ﹤0.01% |
100
| – | – |
|
7957
PUT
Benitec Biopharma
BNTC
$468M
| $1.35K | ﹤0.01% |
100
| – | – |
|
7958
Codexis
CDXS
$158M
| $1.34K | ﹤0.01% |
+824
| New | +$1.68K |
|
7959
CALL
Envela
ELA
$446M
| $1.34K | ﹤0.01% |
+100
| New | +$1.04K |
|
7960
OPAL Fuels
OPAL
$70.7M
| $1.32K | ﹤0.01% |
+562
| New | +$1.35K |
|
7961
VanEck Fallen Angel High Yield Bond ETF
ANGL
$3.11B
| $1.32K | ﹤0.01% |
+45
| New | +$1.32K |
|
7962
PUT
Spok Holdings
SPOK
$241M
| $1.32K | ﹤0.01% |
100
-1,000
| -91% | -$14.2K |
|
|
JAMF
7963
PUT
DELISTED
Jamf
JAMF
| $1.3K | ﹤0.01% |
100
-900
| -90% | -$10.9K |
|
7964
CALL
Navient
NAVI
$853M
| $1.3K | ﹤0.01% |
100
-8,200
| -99% | -$102K |
|
7965
CALL
Mammoth Energy Services
TUSK
$163M
| $1.29K | ﹤0.01% |
700
-14,900
| -96% | -$30.1K |
|
7966
Aware
AWRE
$27.7M
| $1.28K | ﹤0.01% |
695
-3,551
| -84% | -$8.02K |
|
7967
PUT
Valens Semiconductor
VLN
$188M
| $1.28K | ﹤0.01% |
900
-400
| -31% | -$659 |
|
7968
Neurogene
NGNE
$712M
| $1.28K | ﹤0.01% |
62
-1,172
| -95% | -$29.2K |
|
7969
CALL
ADS-TEC Energy
ADSE
$889M
| $1.27K | ﹤0.01% |
+100
| New | +$1.12K |
|
|
7970
PUT
ADS-TEC Energy
ADSE
$889M
| $1.27K | ﹤0.01% |
+100
| New | +$1.12K |
|
7971
CALL
Amtech Systems
ASYS
$272M
| $1.25K | ﹤0.01% |
100
-7,100
| -99% | -$64K |
|
7972
Direxion Daily S&P 500 Bear 1X ETF
SPDN
$199M
| $1.25K | ﹤0.01% |
133
-800
| -86% | -$7.63K |
|
|
STRZ
7973
Starz Entertainment Corp
STRZ
$440M
| $1.25K | ﹤0.01% |
+107
| New | +$1.23K |
|
7974
CALL
Dolphin Entertainment
DLPN
$14.3M
| $1.25K | ﹤0.01% |
+800
| New | +$1.26K |
|
7975
CALL
ReposiTrak
TRAK
$159M
| $1.24K | ﹤0.01% |
+100
| New | +$1.42K |
|
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.