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 | |
|---|---|---|---|---|---|---|
1801
CALL
Tidewater
TDW
$3.91B
| $2.5M | ﹤0.01% |
49,400
-2,300
| -4% | -$121K |
|
1802
CALL
Ambarella
AMBA
$2.99B
| $2.49M | ﹤0.01% |
35,200
+10,200
| +41% | +$824K |
|
1803
CALL
Pool Corp
POOL
$6.7B
| $2.49M | ﹤0.01% |
10,900
+10,200
| +1,457% | +$2.65M |
|
1804
PUT
Enovix
ENVX
$862M
| $2.49M | ﹤0.01% |
340,000
-305,800
| -47% | -$2.96M |
|
1805
CALL
GoDaddy
GDDY
$12.3B
| $2.48M | ﹤0.01% |
20,000
-4,000
| -17% | -$518K |
|
1806
PUT
Harley-Davidson
HOG
$2.68B
| $2.48M | ﹤0.01% |
121,100
-161,200
| -57% | -$3.96M |
|
1807
CALL
McEwen Inc
MUX
$1.03B
| $2.48M | ﹤0.01% |
134,000
-271,000
| -67% | -$5.04M |
|
|
CTRA
1808
PUT
DELISTED
Coterra Energy
CTRA
| $2.48M | ﹤0.01% |
94,100
-44,300
| -32% | -$1.12M |
|
|
PPLC
1809
CALL
DELISTED
PortfolioPlus S&P 500 ETF
PPLC
| $2.47M | ﹤0.01% |
77,600
-186,800
| -71% | -$5.95M |
|
1810
PUT
Insulet
PODD
$11.3B
| $2.47M | ﹤0.01% |
8,700
-1,500
| -15% | -$469K |
|
|
BABO
1811
PUT
YieldMax BABA Option Income Strategy ETF
BABO
$13.7M
| $2.47M | ﹤0.01% |
118,000
+46,300
| +65% | +$704K |
|
1812
CALL
Parker-Hannifin
PH
$125B
| $2.46M | ﹤0.01% |
2,800
-1,500
| -35% | -$1.23M |
|
1813
UBS Group
UBS
$170B
| $2.46M | ﹤0.01% |
53,030
-56,918
| -52% | -$2.3M |
|
1814
Unilever
UL
$131B
| $2.45M | ﹤0.01% |
+37,532
| New | +$2.52M |
|
|
HSAI
1815
CALL
Hesai Group
HSAI
$2.29B
| $2.45M | ﹤0.01% |
109,500
-52,000
| -32% | -$1.14M |
|
1816
PUT
NetEase
NTES
$76.5B
| $2.45M | ﹤0.01% |
17,800
-22,700
| -56% | -$3.22M |
|
1817
PUT
KE Holdings
BEKE
$16.8B
| $2.45M | ﹤0.01% |
155,300
-52,500
| -25% | -$902K |
|
1818
iShares iBoxx $ High Yield Corporate Bond ETF
HYG
$16.3B
| $2.45M | ﹤0.01% |
+30,347
| New | +$2.45M |
|
1819
PUT
Cogent Biosciences
COGT
$6.79B
| $2.44M | ﹤0.01% |
68,600
+5,400
| +9% | +$152K |
|
1820
PUT
Leggett & Platt
LEG
$1.52B
| $2.44M | ﹤0.01% |
221,400
+209,700
| +1,792% | +$2.06M |
|
1821
Robinhood
HOOD
$85.2B
| $2.43M | ﹤0.01% |
21,529
+82
| +0.4% | +$10.7K |
|
1822
PUT
PENN Entertainment
PENN
$2.74B
| $2.43M | ﹤0.01% |
164,900
-175,700
| -52% | -$2.74M |
|
1823
PUT
Crescent Energy
CRGY
$3.72B
| $2.43M | ﹤0.01% |
289,800
+152,100
| +110% | +$1.34M |
|
|
PPTA
1824
CALL
Perpetua Resources
PPTA
$2.23B
| $2.43M | ﹤0.01% |
100,300
-219,400
| -69% | -$5.4M |
|
1825
F5
FFIV
$22.1B
| $2.43M | ﹤0.01% |
+9,503
| New | +$2.56M |
|
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.