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 | |
|---|---|---|---|---|---|---|
2651
InMode
INMD
$872M
| $966K | ﹤0.01% |
65,743
-254,575
| -79% | -$3.75M |
|
|
JBTM
2652
PUT
JBT Marel
JBTM
$7.14B
| $964K | ﹤0.01% |
6,400
+6,200
| +3,100% | +$874K |
|
|
SLI
2653
CALL
Standard Lithium
SLI
$517M
| $963K | ﹤0.01% |
215,400
+204,900
| +1,951% | +$868K |
|
2654
Triple Flag Precious Metals
TFPM
$6B
| $961K | ﹤0.01% |
28,932
+22,850
| +376% | +$715K |
|
2655
Perimeter Solutions
PRM
$5.5B
| $960K | ﹤0.01% |
34,882
+8,401
| +32% | +$212K |
|
|
AEVA
2656
PUT
Aeva Technologies
AEVA
$1.02B
| $960K | ﹤0.01% |
72,300
+66,200
| +1,085% | +$942K |
|
2657
CALL
BellRing Brands
BRBR
$1.51B
| $957K | ﹤0.01% |
35,800
-59,200
| -62% | -$1.84M |
|
2658
PUT
Upwork
UPWK
$1.09B
| $955K | ﹤0.01% |
48,200
-17,000
| -26% | -$312K |
|
2659
CALL
PubMatic
PUBM
$581M
| $955K | ﹤0.01% |
107,700
+41,600
| +63% | +$362K |
|
2660
CALL
Seres Therapeutics
MCRB
$48M
| $955K | ﹤0.01% |
64,200
-13,300
| -17% | -$232K |
|
2661
PUT
Funko
FNKO
$323M
| $955K | ﹤0.01% |
280,900
-61,900
| -18% | -$195K |
|
2662
CALL
Thor Industries
THO
$3.99B
| $955K | ﹤0.01% |
9,300
-100
| -1% | -$10.4K |
|
2663
CALL
Performance Food Group
PFGC
$17.5B
| $953K | ﹤0.01% |
10,600
+10,300
| +3,433% | +$995K |
|
|
EMBJ
2664
Embraer S.A. ADS
EMBJ
$11.6B
| $953K | ﹤0.01% |
+14,804
| New | +$928K |
|
2665
CALL
Bruker
BRKR
$9.2B
| $952K | ﹤0.01% |
20,200
-39,700
| -66% | -$1.68M |
|
2666
PUT
Harrow
HROW
$1.43B
| $951K | ﹤0.01% |
19,400
-1,800
| -8% | -$75.6K |
|
2667
PUT
FS KKR Capital
FSK
$2.98B
| $949K | ﹤0.01% |
64,100
-109,800
| -63% | -$1.66M |
|
2668
Direxion Daily Energy Bull 2X ETF
ERX
$249M
| $946K | ﹤0.01% |
16,947
+13,579
| +403% | +$753K |
|
|
CNH
2669
CALL
CNH Industrial
CNH
$13.8B
| $946K | ﹤0.01% |
102,600
+7,700
| +8% | +$76.9K |
|
2670
MasterBrand
MBC
$1.09B
| $946K | ﹤0.01% |
+85,678
| New | +$1M |
|
2671
PUT
Triumph Financial Inc
TFIN
$1.84B
| $946K | ﹤0.01% |
+15,100
| New | +$846K |
|
|
NUVL
2672
CALL
DELISTED
Nuvalent
NUVL
| $946K | ﹤0.01% |
+9,400
| New | +$927K |
|
2673
PUT
F5
FFIV
$22.1B
| $944K | ﹤0.01% |
3,700
+400
| +12% | +$108K |
|
2674
PUT
Organon & Co
OGN
$3.55B
| $944K | ﹤0.01% |
131,700
-4,100
| -3% | -$32.4K |
|
2675
Cboe Global Markets
CBOE
$29.8B
| $944K | ﹤0.01% |
3,761
-1,630
| -30% | -$405K |
|
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.