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 |
Alibaba
BABA
|
+$120M |
| 2 |
Alphabet (Google) Class A
GOOGL
|
+$93.9M |
| 3 |
Walt Disney
DIS
|
+$71.7M |
| 4 |
KraneShares CSI China Internet ETF
KWEB
|
+$41.7M |
| 5 |
Citigroup
C
|
+$39.4M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$136M |
| 2 |
Amazon
AMZN
|
+$118M |
| 3 |
SPDR Gold Trust
GLD
|
+$56.2M |
| 4 |
Microsoft
MSFT
|
+$52.4M |
| 5 |
State Street SPDR Dow Jones Industrial Average ETF Trust
DIA
|
+$45.6M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.33% |
| 2 | Consumer Discretionary | 0.3% |
| 3 | Communication Services | 0.21% |
| 4 | Financials | 0.19% |
| 5 | Healthcare | 0.19% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
2476
PUT
AGCO
AGCO
$8.78B
| $1.75M | ﹤0.01% |
14,400
+6,500
| +82% | +$760K |
|
2477
PUT
AvePoint
AVPT
$2.6B
| $1.75M | ﹤0.01% |
212,900
+205,000
| +2,595% | +$1.6M |
|
2478
CALL
Lattice Semiconductor
LSCC
$17.6B
| $1.75M | ﹤0.01% |
25,300
-25,100
| -50% | -$1.67M |
|
2479
PUT
Fluence Energy
FLNC
$1.78B
| $1.74M | ﹤0.01% |
73,100
+64,100
| +712% | +$1.35M |
|
2480
CALL
Assurant
AIZ
$13.7B
| $1.74M | ﹤0.01% |
10,300
+9,600
| +1,371% | +$1.53M |
|
2481
PUT
Starwood Property Trust
STWD
$6.12B
| $1.73M | ﹤0.01% |
82,500
+21,600
| +35% | +$424K |
|
2482
CALL
Vista Energy
VIST
$7.75B
| $1.73M | ﹤0.01% |
58,700
+1,500
| +3% | +$44.2K |
|
2483
CALL
Avantor
AVTR
$7.81B
| $1.72M | ﹤0.01% |
75,500
-19,900
| -21% | -$408K |
|
2484
CALL
Emcor
EME
$33.1B
| $1.72M | ﹤0.01% |
8,000
-1,300
| -14% | -$273K |
|
2485
GitLab
GTLB
$5.28B
| $1.72M | ﹤0.01% |
27,353
+20,738
| +313% | +$1.05M |
|
2486
PUT
Natera
NTRA
$37.5B
| $1.72M | ﹤0.01% |
27,500
-5,700
| -17% | -$285K |
|
2487
PUT
Synaptics
SYNA
$4.41B
| $1.72M | ﹤0.01% |
15,100
+9,500
| +170% | +$943K |
|
2488
First Majestic Silver
AG
$8.05B
| $1.72M | ﹤0.01% |
279,070
-119,561
| -30% | -$659K |
|
|
MASI
2489
DELISTED
Masimo
MASI
| $1.72M | ﹤0.01% |
14,646
-36,043
| -71% | -$3.36M |
|
2490
PUT
Fortive
FTV
$19B
| $1.72M | ﹤0.01% |
30,919
-12,474
| -29% | -$658K |
|
|
IPG
2491
DELISTED
Interpublic Group of Companies
IPG
| $1.71M | ﹤0.01% |
+52,497
| New | +$1.58M |
|
2492
PUT
Westrock Coffee
WEST
$741M
| $1.71M | ﹤0.01% |
167,800
+42,900
| +34% | +$384K |
|
|
BIG
2493
CALL
DELISTED
Big Lots, Inc.
BIG
| $1.71M | ﹤0.01% |
220,000
+29,400
| +15% | +$151K |
|
2494
PUT
Grab
GRAB
$13.5B
| $1.71M | ﹤0.01% |
507,600
+166,400
| +49% | +$538K |
|
2495
PUT
Cal-Maine
CALM
$4.28B
| $1.7M | ﹤0.01% |
29,700
+9,000
| +43% | +$445K |
|
2496
CALL
Invesco
IVZ
$13.3B
| $1.7M | ﹤0.01% |
95,500
+58,900
| +161% | +$850K |
|
2497
PUT
Ardelyx
ARDX
$1.24B
| $1.7M | ﹤0.01% |
274,400
-23,600
| -8% | -$106K |
|
2498
PUT
Artisan Partners
APAM
$2.79B
| $1.7M | ﹤0.01% |
38,500
+25,400
| +194% | +$958K |
|
2499
PUT
Vanguard Emerging Markets Government Bond ETF
VWOB
$6.15B
| $1.7M | ﹤0.01% |
15,400
-8,400
| -35% | -$506K |
|
2500
argenx
ARGX
$57.4B
| $1.69M | ﹤0.01% |
4,446
-352
| -7% | -$164K |
|
Similar funds
Simplex Trading's Q4 2023 Portfolio in Review
As of Q4 2023, Simplex Trading held 10,333 positions worth $156B, up 23% from $127B the previous quarter. Its ten largest holdings account for 42% of the portfolio.
Simplex Trading deployed $15.1B of net new capital in Q4 2023, opening 1,639 new positions and adding to 3,920 existing holdings. Its largest new stake was Walt Disney: 812,984 shares worth $73.4M.
By sector, the portfolio is most concentrated in Technology at 0.33% of assets, down from 0.44% a quarter earlier, followed by Consumer Discretionary and Communication Services.
On the sell side, the largest reduction was iShares 20+ Year Treasury Bond ETF, an estimated $136M trimmed.
- Simplex Trading's largest Q4 2023 buy was Walt Disney: 812,984 shares worth $73.4M.
- Simplex Trading added most to Alibaba in Q4 2023, an estimated $120M increase.
- Simplex Trading's biggest Q4 2023 reduction was iShares 20+ Year Treasury Bond ETF, cutting an estimated $136M.
- Simplex Trading fully exited Amazon in Q4 2023, selling an estimated $118M.
- Simplex Trading's ten largest holdings make up 42% of its $156B portfolio in Q4 2023.
- Simplex Trading opened 1,639 new positions and closed 1,508 in Q4 2023.
- Simplex Trading's portfolio value rose 23% quarter-over-quarter to $156B.
Based on Simplex Trading's 13F filing for Q4 2023, filed 2 Feb 2024.