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 | |
|---|---|---|---|---|---|---|
26
PUT
Palantir
PLTR
$318B
| $1.08B | 0.61% |
6,072,300
+842,200
| +16% | +$152M |
|
|
27
PUT
Amazon
AMZN
$2.66T
| $1.01B | 0.57% |
4,358,100
-731,800
| -14% | -$167M |
|
28
CALL
Advanced Micro Devices
AMD
$888B
| $978M | 0.55% |
4,566,700
-915,100
| -17% | -$206M |
|
|
29
PUT
Netflix
NFLX
$286B
| $943M | 0.53% |
10,059,900
+884,900
| +10% | +$95.4M |
|
30
CALL
UnitedHealth
UNH
$396B
| $920M | 0.52% |
2,787,700
-190,100
| -6% | -$64.4M |
|
|
31
CALL
Netflix
NFLX
$286B
| $912M | 0.51% |
9,724,800
+3,115,800
| +47% | +$336M |
|
32
CALL
Broadcom
AVGO
$1.84T
| $900M | 0.51% |
2,600,600
-120,100
| -4% | -$42.9M |
|
33
CALL
iShares Bitcoin Trust
IBIT
$48.9B
| $888M | 0.5% |
17,890,100
+725,800
| +4% | +$41.2M |
|
34
PUT
VanEck Gold Miners ETF
GDX
$22.7B
| $848M | 0.48% |
4,735,900
-879,100
| -16% | -$69.4M |
|
|
35
PUT
Advanced Micro Devices
AMD
$888B
| $811M | 0.46% |
3,786,200
-572,900
| -13% | -$129M |
|
36
CALL
State Street Materials Select Sector SPDR ETF
XLB
$8.31B
| $769M | 0.43% |
11,518,300
-8,610,300
| -43% | -$381M |
|
37
PUT
iShares Silver Trust
SLV
$28.4B
| $729M | 0.41% |
11,310,200
+4,201,600
| +59% | +$210M |
|
38
PUT
Strategy Inc
MSTR
$37B
| $583M | 0.33% |
3,851,200
-977,400
| -20% | -$225M |
|
39
CALL
Oracle
ORCL
$366B
| $561M | 0.32% |
2,877,400
+494,300
| +21% | +$118M |
|
|
40
PUT
UnitedHealth
UNH
$396B
| $536M | 0.3% |
1,623,900
-130,300
| -7% | -$44.2M |
|
41
PUT
Micron Technology
MU
$1.1T
| $497M | 0.28% |
1,741,100
-287,100
| -14% | -$65.9M |
|
|
42
CALL
Alibaba
BABA
$283B
| $491M | 0.28% |
3,483,000
-1,461,800
| -30% | -$238M |
|
43
PUT
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
$46B
| $457M | 0.26% |
951,000
+522,800
| +122% | +$247M |
|
44
PUT
State Street SPDR NYSE Technology ETF
XNTK
$2.16B
| $443M | 0.25% |
5,034,000
-1,118,700
| -18% | -$313M |
|
|
45
PUT
Oracle
ORCL
$366B
| $435M | 0.25% |
2,232,600
+205,000
| +10% | +$48.8M |
|
46
PUT
iShares Morningstar Value ETF
ILCV
$1.3B
| $434M | 0.24% |
5,327,600
+558,800
| +12% | +$51.7M |
|
|
47
PUT
iShares Bitcoin Trust
IBIT
$48.9B
| $430M | 0.24% |
8,660,500
-1,599,400
| -16% | -$90.9M |
|
|
48
CALL
Strategy Inc
MSTR
$37B
| $425M | 0.24% |
2,835,200
+108,300
| +4% | +$24.9M |
|
49
CALL
Intel
INTC
$530B
| $418M | 0.24% |
11,326,800
-2,473,200
| -18% | -$93.4M |
|
|
50
CALL
Micron Technology
MU
$1.1T
| $400M | 0.23% |
1,400,600
-1,472,600
| -51% | -$338M |
|
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.