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 | |
|---|---|---|---|---|---|---|
1751
CALL
The RealReal
REAL
$1.34B
| $2.66M | ﹤0.01% |
168,700
-98,600
| -37% | -$1.29M |
|
1752
CALL
Matador Resources
MTDR
$6.31B
| $2.65M | ﹤0.01% |
62,500
-4,700
| -7% | -$197K |
|
1753
CALL
Nektar Therapeutics
NKTR
$2.39B
| $2.65M | ﹤0.01% |
62,700
-5,900
| -9% | -$330K |
|
1754
PUT
Apogee Therapeutics
APGE
$10.2B
| $2.65M | ﹤0.01% |
35,100
+32,300
| +1,154% | +$2.03M |
|
1755
uniQure
QURE
$2.68B
| $2.65M | ﹤0.01% |
110,675
+42,680
| +63% | +$1.65M |
|
1756
Moderna
MRNA
$21.5B
| $2.64M | ﹤0.01% |
89,676
-245,712
| -73% | -$6.68M |
|
1757
Lumen
LUMN
$6.53B
| $2.63M | ﹤0.01% |
+338,757
| New | +$2.79M |
|
1758
CALL
Levi Strauss
LEVI
$9.44B
| $2.63M | ﹤0.01% |
126,800
+8,900
| +8% | +$192K |
|
1759
CALL
Vornado Realty Trust
VNO
$7.47B
| $2.63M | ﹤0.01% |
78,900
-10,000
| -11% | -$365K |
|
1760
PUT
Hasbro
HAS
$12.6B
| $2.62M | ﹤0.01% |
32,000
-10,700
| -25% | -$839K |
|
1761
CALL
Lamb Weston
LW
$6.82B
| $2.62M | ﹤0.01% |
62,500
-5,600
| -8% | -$330K |
|
1762
PUT
Vail Resorts
MTN
$5.19B
| $2.62M | ﹤0.01% |
19,700
-12,800
| -39% | -$1.88M |
|
1763
CALL
Arthur J. Gallagher & Co
AJG
$63.7B
| $2.61M | ﹤0.01% |
10,100
-34,300
| -77% | -$9.08M |
|
1764
PUT
Enterprise Products Partners
EPD
$83.8B
| $2.61M | ﹤0.01% |
81,400
+4,700
| +6% | +$149K |
|
1765
PUT
Robert Half
RHI
$3.61B
| $2.6M | ﹤0.01% |
95,900
+35,200
| +58% | +$1M |
|
1766
CALL
Cogent Biosciences
COGT
$6.79B
| $2.6M | ﹤0.01% |
73,300
+54,100
| +282% | +$1.52M |
|
1767
PUT
Goodyear
GT
$2.07B
| $2.6M | ﹤0.01% |
296,500
-257,900
| -47% | -$2.03M |
|
1768
CALL
Consolidated Edison
ED
$41.6B
| $2.59M | ﹤0.01% |
26,100
-31,100
| -54% | -$3.09M |
|
1769
Vanguard High Dividend Yield ETF
VYM
$81.1B
| $2.59M | ﹤0.01% |
18,061
-7,130
| -28% | -$1.01M |
|
1770
PUT
BioMarin Pharmaceuticals
BMRN
$11.5B
| $2.59M | ﹤0.01% |
43,600
-18,600
| -30% | -$1.01M |
|
1771
CALL
Ouster
OUST
$2.29B
| $2.59M | ﹤0.01% |
119,700
+100
| +0.1% | +$2.64K |
|
1772
CALL
BioNTech
BNTX
$22.6B
| $2.59M | ﹤0.01% |
27,200
-22,300
| -45% | -$2.25M |
|
1773
CALL
Roivant Sciences
ROIV
$25.2B
| $2.59M | ﹤0.01% |
119,200
-143,900
| -55% | -$2.84M |
|
1774
American Tower
AMT
$77.7B
| $2.59M | ﹤0.01% |
14,732
+5,044
| +52% | +$918K |
|
1775
Fabrinet
FN
$17.1B
| $2.58M | ﹤0.01% |
5,673
+3,169
| +127% | +$1.38M |
|
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.