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 | |
|---|---|---|---|---|---|---|
1826
CALL
Lincoln National
LNC
$7.91B
| $2.41M | ﹤0.01% |
54,200
-19,800
| -27% | -$825K |
|
1827
Pitney Bowes
PBI
$2.42B
| $2.41M | ﹤0.01% |
228,269
-123,061
| -35% | -$1.28M |
|
1828
BP
BP
$113B
| $2.41M | ﹤0.01% |
69,469
+27,432
| +65% | +$962K |
|
1829
PUT
Argan
AGX
$7.98B
| $2.41M | ﹤0.01% |
7,700
-5,500
| -42% | -$1.75M |
|
1830
CALL
ASP Isotopes
ASPI
$487M
| $2.41M | ﹤0.01% |
450,400
+99,300
| +28% | +$790K |
|
1831
CALL
Capri Holdings
CPRI
$1.77B
| $2.41M | ﹤0.01% |
98,700
-93,300
| -49% | -$2.16M |
|
1832
PUT
Plains All American Pipeline
PAA
$17.4B
| $2.4M | ﹤0.01% |
133,900
+3,300
| +3% | +$56.1K |
|
1833
iShares National Muni Bond ETF
MUB
$45.1B
| $2.4M | ﹤0.01% |
+22,387
| New | +$2.4M |
|
1834
CALL
Global E Online
GLBE
$6.08B
| $2.39M | ﹤0.01% |
60,900
-91,300
| -60% | -$3.39M |
|
1835
PUT
Emcor
EME
$33.1B
| $2.39M | ﹤0.01% |
3,900
+3,100
| +388% | +$2.01M |
|
1836
CALL
Ocular Therapeutix
OCUL
$1.86B
| $2.37M | ﹤0.01% |
195,600
-56,500
| -22% | -$686K |
|
|
DQ
1837
CALL
Daqo New Energy
DQ
$790M
| $2.37M | ﹤0.01% |
80,400
-42,300
| -34% | -$1.29M |
|
1838
PUT
Barclays
BCS
$94.1B
| $2.37M | ﹤0.01% |
93,100
-103,600
| -53% | -$2.29M |
|
1839
ProShares UltraShort Bitcoin ETF
SBIT
$163M
| $2.37M | ﹤0.01% |
+53,905
| New | +$1.98M |
|
1840
CALL
Sphere Entertainment
SPHR
$4.88B
| $2.37M | ﹤0.01% |
24,900
-30,000
| -55% | -$2.29M |
|
1841
PUT
Papa John's
PZZA
$999M
| $2.37M | ﹤0.01% |
61,500
+41,800
| +212% | +$1.85M |
|
1842
CALL
Paycom
PAYC
$6.78B
| $2.36M | ﹤0.01% |
14,800
+6,000
| +68% | +$1.06M |
|
|
SEI
1843
CALL
Solaris Energy Infrastructure
SEI
$3.31B
| $2.35M | ﹤0.01% |
51,200
-51,200
| -50% | -$2.48M |
|
1844
PUT
Franklin Resources
BEN
$16.9B
| $2.35M | ﹤0.01% |
98,500
+29,600
| +43% | +$680K |
|
|
DAY
1845
CALL
DELISTED
Dayforce
DAY
| $2.34M | ﹤0.01% |
33,900
-24,800
| -42% | -$1.71M |
|
|
TTAN
1846
CALL
ServiceTitan Inc
TTAN
$6.72B
| $2.34M | ﹤0.01% |
22,000
+15,000
| +214% | +$1.47M |
|
1847
CALL
Herbalife
HLF
$1.23B
| $2.34M | ﹤0.01% |
181,700
-63,600
| -26% | -$673K |
|
1848
PUT
iPath Series B S&P 500 VIX Short-Term Futures ETN
VXX
$162M
| $2.34M | ﹤0.01% |
98,300
-187,200
| -66% | -$6.12M |
|
1849
CALL
Trane Technologies
TT
$106B
| $2.34M | ﹤0.01% |
6,000
-1,400
| -19% | -$579K |
|
1850
CALL
Domo
DOMO
$166M
| $2.33M | ﹤0.01% |
276,700
+238,000
| +615% | +$2.8M |
|
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.