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 | |
|---|---|---|---|---|---|---|
2351
ProShares Trust UltraShort Lehman 20+ Year Treasury
TBT
$293M
| $1.32M | ﹤0.01% |
37,809
-17,616
| -32% | -$592K |
|
2352
CALL
Banco Santander
SAN
$194B
| $1.32M | ﹤0.01% |
112,400
-284,600
| -72% | -$3.02M |
|
2353
CALL
PennyMac Financial
PFSI
$4.38B
| $1.32M | ﹤0.01% |
10,000
-10,400
| -51% | -$1.33M |
|
2354
CALL
BBVA Argentina
BBAR
$3.85B
| $1.32M | ﹤0.01% |
72,900
+5,100
| +8% | +$73.2K |
|
2355
CALL
Global X S&P 500 Tail Risk ETF
XTR
$4.77M
| $1.32M | ﹤0.01% |
28,000
-10,200
| -27% | -$313K |
|
2356
CALL
Perrigo
PRGO
$1.4B
| $1.32M | ﹤0.01% |
94,600
+35,800
| +61% | +$597K |
|
2357
CALL
GlobalFoundries
GFS
$29.4B
| $1.32M | ﹤0.01% |
37,700
-86,400
| -70% | -$3.07M |
|
|
EXE
2358
Expand Energy Corp
EXE
$21.9B
| $1.32M | ﹤0.01% |
11,929
+6,441
| +117% | +$714K |
|
2359
PUT
Enviri
NVRI
$621M
| $1.32M | ﹤0.01% |
73,400
+58,000
| +377% | +$864K |
|
2360
iShares MSCI Turkey ETF
TUR
$206M
| $1.31M | ﹤0.01% |
+38,169
| New | +$1.29M |
|
2361
PUT
Tencent Music
TME
$14.5B
| $1.31M | ﹤0.01% |
74,800
-78,600
| -51% | -$1.59M |
|
|
SA
2362
PUT
Seabridge Gold
SA
$2.8B
| $1.3M | ﹤0.01% |
44,100
+17,700
| +67% | +$465K |
|
2363
PUT
Critical Metals Corp
CRML
$853M
| $1.3M | ﹤0.01% |
188,000
+117,900
| +168% | +$1.29M |
|
2364
PUT
InMode
INMD
$872M
| $1.3M | ﹤0.01% |
88,800
-52,000
| -37% | -$765K |
|
2365
CALL
Arteris
AIP
$1.4B
| $1.3M | ﹤0.01% |
84,000
+53,800
| +178% | +$780K |
|
2366
Banco de Chile
BCH
$20.6B
| $1.3M | ﹤0.01% |
+34,215
| New | +$1.21M |
|
2367
PUT
Icahn Enterprises
IEP
$5.17B
| $1.3M | ﹤0.01% |
172,200
+108,200
| +169% | +$872K |
|
2368
CALL
Viking Holdings
VIK
$44.9B
| $1.3M | ﹤0.01% |
18,200
-22,600
| -55% | -$1.44M |
|
2369
CALL
Douglas Emmett
DEI
$2.06B
| $1.3M | ﹤0.01% |
118,200
+112,900
| +2,130% | +$1.41M |
|
2370
CALL
Cheesecake Factory
CAKE
$4.21B
| $1.3M | ﹤0.01% |
25,700
-13,900
| -35% | -$697K |
|
2371
CALL
Warby Parker
WRBY
$3.01B
| $1.3M | ﹤0.01% |
59,500
+50,700
| +576% | +$1.1M |
|
2372
PUT
Jack Henry & Associates
JKHY
$10.7B
| $1.3M | ﹤0.01% |
7,100
-5,100
| -42% | -$850K |
|
2373
PUT
IAMGOLD
IAG
$8.47B
| $1.29M | ﹤0.01% |
78,500
-96,800
| -55% | -$1.36M |
|
|
QXO
2374
PUT
QXO Inc
QXO
$14.2B
| $1.29M | ﹤0.01% |
67,100
-171,800
| -72% | -$3.29M |
|
2375
CALL
Diageo
DEO
$46.2B
| $1.29M | ﹤0.01% |
15,000
-33,300
| -69% | -$3.07M |
|
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.