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 | |
|---|---|---|---|---|---|---|
3026
PUT
Freshpet
FRPT
$2.92B
| $664K | ﹤0.01% |
10,900
-22,400
| -67% | -$1.27M |
|
3027
Enovix
ENVX
$923M
| $662K | ﹤0.01% |
90,575
-157,453
| -63% | -$1.53M |
|
3028
CALL
Precigen
PGEN
$1.93B
| $660K | ﹤0.01% |
157,800
-148,500
| -48% | -$575K |
|
|
CRON
3029
PUT
Cronos Group
CRON
$1.07B
| $659K | ﹤0.01% |
250,500
-318,300
| -56% | -$823K |
|
3030
PUT
Aecom
ACM
$9.12B
| $658K | ﹤0.01% |
6,900
+1,300
| +23% | +$153K |
|
3031
ProShares UltraShort Silver
ZSL
$64.1M
| $656K | ﹤0.01% |
+12,289
| New | +$1.35M |
|
3032
Hercules Capital
HTGC
$2.95B
| $655K | ﹤0.01% |
34,820
+16,544
| +91% | +$298K |
|
3033
CALL
Yext
YEXT
$554M
| $654K | ﹤0.01% |
81,100
-79,000
| -49% | -$665K |
|
3034
MannKind Corp
MNKD
$1.22B
| $653K | ﹤0.01% |
115,191
+2,054
| +2% | +$11.3K |
|
3035
CALL
nVent Electric
NVT
$24.1B
| $653K | ﹤0.01% |
6,400
-28,000
| -81% | -$2.91M |
|
3036
CALL
Chegg
CHGG
$110M
| $652K | ﹤0.01% |
701,400
+251,200
| +56% | +$274K |
|
|
FETH
3037
PUT
Fidelity Ethereum Fund
FETH
$1.05B
| $651K | ﹤0.01% |
22,000
-7,700
| -26% | -$266K |
|
3038
CALL
TFI International
TFII
$12B
| $651K | ﹤0.01% |
6,300
-200
| -3% | -$18.6K |
|
3039
Papa John's
PZZA
$997M
| $650K | ﹤0.01% |
+16,889
| New | +$746K |
|
3040
CALL
Olin
OLN
$2.49B
| $650K | ﹤0.01% |
31,200
-59,200
| -65% | -$1.28M |
|
3041
CALL
Tenaris
TS
$28.5B
| $650K | ﹤0.01% |
16,900
-17,100
| -50% | -$659K |
|
3042
CALL
Liberty Energy
LBRT
$2.75B
| $650K | ﹤0.01% |
35,200
-74,700
| -68% | -$1.25M |
|
|
3043
CALL
MannKind Corp
MNKD
$1.22B
| $650K | ﹤0.01% |
114,600
-164,600
| -59% | -$906K |
|
3044
Sanmina
SANM
$11.2B
| $650K | ﹤0.01% |
+4,328
| New | +$639K |
|
3045
CALL
Americold
COLD
$4.17B
| $649K | ﹤0.01% |
50,500
+34,400
| +214% | +$422K |
|
3046
Sonos
SONO
$1.87B
| $648K | ﹤0.01% |
36,883
-102,636
| -74% | -$1.79M |
|
3047
PUT
Performance Food Group
PFGC
$18B
| $647K | ﹤0.01% |
7,200
-25,700
| -78% | -$2.48M |
|
3048
CALL
Rush Enterprises Class A
RUSHA
$5.98B
| $647K | ﹤0.01% |
12,000
-6,200
| -34% | -$322K |
|
3049
CALL
Vicor
VICR
$9.41B
| $647K | ﹤0.01% |
5,900
+5,700
| +2,850% | +$485K |
|
3050
CALL
Howard Hughes
HHH
$3.93B
| $646K | ﹤0.01% |
8,100
-14,400
| -64% | -$1.19M |
|
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.