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 |
Microsoft
MSFT
|
+$234M |
| 2 |
iShares Russell 2000 ETF
IWM
|
+$97.5M |
| 3 |
Amazon
AMZN
|
+$96.8M |
| 4 |
iShares Bitcoin Trust
IBIT
|
+$80.6M |
| 5 |
Pinduoduo
PDD
|
+$54.9M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$129M |
| 2 |
Alphabet (Google) Class A
GOOGL
|
+$92.9M |
| 3 |
Broadcom
AVGO
|
+$82.9M |
| 4 |
Alphabet (Google) Class C
GOOG
|
+$68.4M |
| 5 |
Meta Platforms (Facebook)
META
|
+$59.2M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.79% |
| 2 | Consumer Discretionary | 0.3% |
| 3 | Healthcare | 0.25% |
| 4 | Financials | 0.17% |
| 5 | Industrials | 0.09% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
2676
Darling Ingredients
DAR
$9.93B
| $1.43M | ﹤0.01% |
46,314
-3,119
| -6% | -$104K |
|
2677
PUT
Church & Dwight Co
CHD
$23.1B
| $1.43M | ﹤0.01% |
16,300
-6,600
| -29% | -$619K |
|
2678
Arcus Biosciences
RCUS
$3.57B
| $1.43M | ﹤0.01% |
105,025
+3,825
| +4% | +$39.8K |
|
2679
PUT
National Grid
NGG
$82.7B
| $1.42M | ﹤0.01% |
19,881
+11,158
| +128% | +$783K |
|
2680
CALL
Arcutis Biotherapeutics
ARQT
$3.42B
| $1.42M | ﹤0.01% |
75,500
-15,100
| -17% | -$238K |
|
2681
PUT
GoDaddy
GDDY
$12.3B
| $1.42M | ﹤0.01% |
10,400
-9,500
| -48% | -$1.46M |
|
|
ONT
2682
CALL
Onterris Inc
ONT
$710M
| $1.42M | ﹤0.01% |
51,800
-24,900
| -32% | -$651K |
|
2683
PUT
Ball Corp
BALL
$17B
| $1.42M | ﹤0.01% |
28,200
-76,700
| -73% | -$4.15M |
|
2684
CALL
Gartner
IT
$9.41B
| $1.42M | ﹤0.01% |
5,400
+2,800
| +108% | +$817K |
|
2685
Cinemark Holdings
CNK
$3.82B
| $1.42M | ﹤0.01% |
50,589
-29,592
| -37% | -$817K |
|
2686
Universal Technical Institute
UTI
$2.08B
| $1.42M | ﹤0.01% |
+43,489
| New | +$1.28M |
|
2687
CALL
ClearPoint Neuro
CLPT
$423M
| $1.41M | ﹤0.01% |
64,900
+60,200
| +1,281% | +$709K |
|
2688
CALL
Aurinia Pharmaceuticals
AUPH
$1.97B
| $1.41M | ﹤0.01% |
127,900
-65,000
| -34% | -$710K |
|
2689
Cheniere Energy
LNG
$56.5B
| $1.41M | ﹤0.01% |
+6,017
| New | +$1.41M |
|
2690
BrightSpring Health Services
BTSG
$14.3B
| $1.41M | ﹤0.01% |
47,812
+45,673
| +2,135% | +$1.06M |
|
2691
Harmony Gold Mining
HMY
$9.92B
| $1.41M | ﹤0.01% |
77,833
+64,170
| +470% | +$969K |
|
2692
CALL
The Oncology Institute
TOI
$498M
| $1.41M | ﹤0.01% |
+403,200
| New | +$1.38M |
|
|
SPR
2693
PUT
DELISTED
Spirit AeroSystems
SPR
| $1.41M | ﹤0.01% |
36,400
+400
| +1% | +$16K |
|
2694
PUT
AptarGroup
ATR
$8.45B
| $1.4M | ﹤0.01% |
10,500
+4,000
| +62% | +$578K |
|
2695
Equity Residential
EQR
$25.4B
| $1.4M | ﹤0.01% |
+21,690
| New | +$1.42M |
|
2696
PUT
Comfort Systems
FIX
$61B
| $1.4M | ﹤0.01% |
1,700
-1,100
| -39% | -$746K |
|
|
HOLX
2697
DELISTED
Hologic
HOLX
| $1.4M | ﹤0.01% |
20,783
+17,207
| +481% | +$1.14M |
|
2698
CALL
Weyerhaeuser
WY
$17.3B
| $1.4M | ﹤0.01% |
56,500
+2,900
| +5% | +$74.1K |
|
2699
PUT
Gogo Inc
GOGO
$515M
| $1.4M | ﹤0.01% |
162,900
-62,600
| -28% | -$794K |
|
2700
PUT
Virgin Galactic
SPCE
$320M
| $1.4M | ﹤0.01% |
361,900
+224,000
| +162% | +$751K |
|
Similar funds
Simplex Trading's Q3 2025 Portfolio in Review
As of Q3 2025, Simplex Trading held 10,358 positions worth $195B, up 12% from $175B the previous quarter. Its ten largest holdings account for 46% of the portfolio.
Simplex Trading's Q3 2025 filing shows 1,743 new, 3,828 increased, 3,250 reduced and 1,308 closed positions. Its largest new stake was Microsoft: 458,309 shares worth $237M. The largest sale was iShares 20+ Year Treasury Bond ETF, an estimated $129M.
By sector, the portfolio is most concentrated in Technology at 0.79% of assets, up from 0.74% a quarter earlier, followed by Consumer Discretionary and Healthcare.
- Simplex Trading's largest Q3 2025 buy was Microsoft: 458,309 shares worth $237M.
- Simplex Trading added most to iShares Russell 2000 ETF in Q3 2025, an estimated $97.5M increase.
- Simplex Trading's biggest Q3 2025 reduction was Alphabet (Google) Class A, cutting an estimated $92.9M.
- Simplex Trading fully exited iShares 20+ Year Treasury Bond ETF in Q3 2025, selling an estimated $129M.
- Simplex Trading's ten largest holdings make up 46% of its $195B portfolio in Q3 2025.
- Simplex Trading opened 1,743 new positions and closed 1,308 in Q3 2025.
- Simplex Trading's portfolio value rose 12% quarter-over-quarter to $195B.
Based on Simplex Trading's 13F filing for Q3 2025, filed 12 Nov 2025.