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 | |
|---|---|---|---|---|---|---|
|
IMSR
2626
CALL
Terrestrial Energy
IMSR
$517M
| $978K | ﹤0.01% |
160,000
+45,400
| +40% | +$607K |
|
2627
ImmunityBio
IBRX
$7.44B
| $977K | ﹤0.01% |
493,445
+453,955
| +1,150% | +$1.03M |
|
2628
Opendoor
OPEN
$3.69B
| $976K | ﹤0.01% |
+182,759
| New | +$1.31M |
|
2629
CALL
Fox Class B
FOX
$20.7B
| $975K | ﹤0.01% |
13,400
+400
| +3% | +$23.4K |
|
2630
CALL
Inter&Co
INTR
$2.34B
| $974K | ﹤0.01% |
114,900
+37,400
| +48% | +$331K |
|
2631
PUT
Genpact
G
$5.3B
| $973K | ﹤0.01% |
20,800
-85,800
| -80% | -$3.71M |
|
2632
CALL
Aecom
ACM
$9.07B
| $972K | ﹤0.01% |
10,200
+1,200
| +13% | +$141K |
|
2633
CALL
Tiptree Inc
TIPT
$668M
| $972K | ﹤0.01% |
53,200
+49,900
| +1,512% | +$909K |
|
2634
PUT
Revolution Medicines
RVMD
$40.2B
| $972K | ﹤0.01% |
12,200
+2,200
| +22% | +$144K |
|
2635
PUT
Millicom
TIGO
$15.8B
| $970K | ﹤0.01% |
17,500
+15,600
| +821% | +$785K |
|
2636
PUT
Karyopharm Therapeutics
KPTI
$168M
| $970K | ﹤0.01% |
131,800
+83,600
| +173% | +$511K |
|
|
MFA
2637
MFA Financial
MFA
$929M
| $970K | ﹤0.01% |
104,143
+34,201
| +49% | +$319K |
|
2638
CALL
Banco Bradesco
BBD
$38.1B
| $969K | ﹤0.01% |
291,000
-37,500
| -11% | -$128K |
|
2639
Hudbay
HBM
$9.92B
| $969K | ﹤0.01% |
+48,814
| New | +$826K |
|
2640
Algonquin Power & Utilities
AQN
$4.69B
| $968K | ﹤0.01% |
157,355
+44,722
| +40% | +$266K |
|
2641
CALL
Polaris
PII
$4.15B
| $968K | ﹤0.01% |
15,300
-8,000
| -34% | -$527K |
|
2642
NewMarket
NEU
$7.17B
| $968K | ﹤0.01% |
1,408
-5,252
| -79% | -$4.01M |
|
2643
YPF
YPF
$20.2B
| $967K | ﹤0.01% |
26,752
-14,107
| -35% | -$468K |
|
|
CHCT
2644
PUT
Community Healthcare Trust
CHCT
$537M
| $967K | ﹤0.01% |
58,900
+57,300
| +3,581% | +$856K |
|
2645
AeroVironment
AVAV
$7.57B
| $967K | ﹤0.01% |
3,998
-3,012
| -43% | -$947K |
|
|
CMPS
2646
CALL
Compass Pathways
CMPS
$1.52B
| $967K | ﹤0.01% |
140,100
+99,100
| +242% | +$604K |
|
2647
CALL
WisdomTree
WT
$2.97B
| $967K | ﹤0.01% |
79,300
+56,800
| +252% | +$686K |
|
2648
CALL
Banc of California
BANC
$3.28B
| $966K | ﹤0.01% |
50,100
-418,000
| -89% | -$7.49M |
|
2649
Roku
ROKU
$21.1B
| $966K | ﹤0.01% |
+8,906
| New | +$904K |
|
|
LINE
2650
CALL
Lineage Inc
LINE
$9.43B
| $966K | ﹤0.01% |
27,600
+10,800
| +64% | +$399K |
|
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.