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 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
1676
PUT
Concentrix
CNXC
$1.82B
| $2.93M | ﹤0.01% |
70,500
+51,300
| +267% | +$2.08M |
|
1677
PUT
Regions Financial
RF
$25.8B
| $2.92M | ﹤0.01% |
107,900
-3,800
| -3% | -$97.1K |
|
1678
CALL
Return Stacked Bonds & Managed Futures ETF
RSBT
$153M
| $2.92M | ﹤0.01% |
163,200
-522,600
| -76% | -$9.46M |
|
|
CHYM
1679
CALL
Chime Financial
CHYM
$12.6B
| $2.92M | ﹤0.01% |
116,000
+65,900
| +132% | +$1.4M |
|
1680
Sharplink Inc
SBET
$1.87B
| $2.91M | ﹤0.01% |
325,973
-428,715
| -57% | -$5.24M |
|
1681
Grab
GRAB
$13.5B
| $2.91M | ﹤0.01% |
583,776
-314,204
| -35% | -$1.74M |
|
1682
CALL
Hormel Foods
HRL
$11.7B
| $2.91M | ﹤0.01% |
122,900
-15,500
| -11% | -$362K |
|
1683
ExxonMobil
XOM
$660B
| $2.9M | ﹤0.01% |
+24,131
| New | +$2.8M |
|
1684
CALL
Camden Property Trust
CPT
$12.2B
| $2.9M | ﹤0.01% |
26,300
+26,100
| +13,050% | +$2.71M |
|
1685
CALL
Boston Properties
BXP
$10.7B
| $2.89M | ﹤0.01% |
42,900
+800
| +2% | +$56.9K |
|
1686
PUT
Banco Macro
BMA
$4.99B
| $2.89M | ﹤0.01% |
32,100
-3,600
| -10% | -$272K |
|
1687
Fortinet
FTNT
$113B
| $2.89M | ﹤0.01% |
+36,413
| New | +$3.02M |
|
1688
CALL
Clear Secure
YOU
$4.49B
| $2.89M | ﹤0.01% |
82,300
+5,600
| +7% | +$191K |
|
1689
GlobalFoundries
GFS
$25.3B
| $2.88M | ﹤0.01% |
82,485
+62,891
| +321% | +$2.24M |
|
1690
Five Below
FIVE
$13.6B
| $2.88M | ﹤0.01% |
+15,289
| New | +$2.49M |
|
1691
CALL
PPG Industries
PPG
$24.6B
| $2.88M | ﹤0.01% |
28,100
-1,300
| -4% | -$131K |
|
1692
Zillow
Z
$7.43B
| $2.88M | ﹤0.01% |
42,155
+7,361
| +21% | +$533K |
|
1693
PUT
ReNew
RNW
$2.5B
| $2.87M | ﹤0.01% |
507,400
-284,100
| -36% | -$2.05M |
|
1694
CALL
Phathom Pharmaceuticals
PHAT
$760M
| $2.86M | ﹤0.01% |
172,300
+111,500
| +183% | +$1.59M |
|
|
ACLX
1695
PUT
DELISTED
Arcellx
ACLX
| $2.86M | ﹤0.01% |
43,800
+41,900
| +2,205% | +$3.34M |
|
1696
Corning
GLW
$144B
| $2.85M | ﹤0.01% |
+32,597
| New | +$2.81M |
|
1697
NuScale Power
SMR
$4.49B
| $2.85M | ﹤0.01% |
201,355
+76,677
| +62% | +$2.19M |
|
|
MPT
1698
Medical Properties Trust
MPT
$2.38B
| $2.85M | ﹤0.01% |
570,485
-494,144
| -46% | -$2.57M |
|
1699
iShares MSCI Global Silver and Metals Miners ETF
SLVP
$1.03B
| $2.85M | ﹤0.01% |
83,189
+81,323
| +4,358% | +$2.39M |
|
1700
Zscaler
ZS
$26.2B
| $2.85M | ﹤0.01% |
12,660
+3,348
| +36% | +$945K |
|
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's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- 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.