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 |
Amazon
AMZN
|
+$113M |
| 2 |
SPDR Gold Trust
GLD
|
+$68.6M |
| 3 |
NVIDIA
NVDA
|
+$63.4M |
| 4 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$55.2M |
| 5 |
Apple
AAPL
|
+$54.9M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
Netflix
NFLX
|
+$27.1M |
| 2 |
Qualcomm
QCOM
|
+$24.6M |
| 3 |
Walt Disney
DIS
|
+$21.2M |
| 4 |
Advanced Micro Devices
AMD
|
+$18.2M |
| 5 |
Snowflake
SNOW
|
+$16.1M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.44% |
| 2 | Consumer Discretionary | 0.32% |
| 3 | Healthcare | 0.22% |
| 4 | Financials | 0.17% |
| 5 | Communication Services | 0.15% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
3876
CALL
Dorman Products
DORM
$4.28B
| $318K | ﹤0.01% |
4,200
+2,000
| +91% | +$163K |
|
3877
CALL
Insmed
INSM
$22.6B
| $318K | ﹤0.01% |
12,600
-27,200
| -68% | -$622K |
|
3878
PUT
Dorian LPG
LPG
$1.9B
| $318K | ﹤0.01% |
11,100
+11,000
| +11,000% | +$296K |
|
3879
CALL
Dragonfly Energy
DFLI
$16.8M
| $317K | ﹤0.01% |
2,290
-590
| -20% | -$104K |
|
3880
CALL
MillerKnoll
MLKN
$1.61B
| $317K | ﹤0.01% |
13,000
+12,600
| +3,150% | +$236K |
|
3881
CALL
Steven Madden
SHOO
$3.22B
| $317K | ﹤0.01% |
10,000
+5,100
| +104% | +$170K |
|
3882
Dana Inc
DAN
$2.95B
| $316K | ﹤0.01% |
+21,576
| New | +$360K |
|
3883
CALL
Glacier Bancorp
GBCI
$6.45B
| $316K | ﹤0.01% |
11,100
+10,600
| +2,120% | +$328K |
|
3884
CALL
Quantum-Si Incorporated
QSI
$166M
| $316K | ﹤0.01% |
190,800
+186,600
| +4,443% | +$449K |
|
3885
PUT
Taysha Gene Therapies
TSHA
$1.57B
| $316K | ﹤0.01% |
100,100
+89,800
| +872% | +$168K |
|
3886
PUT
Eve Holding
EVEX
$853M
| $315K | ﹤0.01% |
38,100
+22,800
| +149% | +$198K |
|
3887
PUT
Green Brick Partners
GRBK
$3.18B
| $315K | ﹤0.01% |
7,600
+6,700
| +744% | +$335K |
|
3888
Webster Financial
WBS
$12.5B
| $315K | ﹤0.01% |
+7,830
| New | +$333K |
|
3889
CALL
A10 Networks
ATEN
$2.25B
| $314K | ﹤0.01% |
20,900
+15,100
| +260% | +$224K |
|
3890
Comstock Resources
CRK
$3.64B
| $314K | ﹤0.01% |
+28,502
| New | +$336K |
|
|
IRBT
3891
CALL
DELISTED
iRobot
IRBT
| $314K | ﹤0.01% |
8,300
-1,800
| -18% | -$72.3K |
|
3892
CALL
Service Corp International
SCI
$11.7B
| $314K | ﹤0.01% |
5,500
-10,200
| -65% | -$644K |
|
|
BORR
3893
CALL
Borr Drilling
BORR
$1.2B
| $313K | ﹤0.01% |
44,200
-120,400
| -73% | -$916K |
|
3894
Calix
CALX
$2.34B
| $313K | ﹤0.01% |
6,843
-5,583
| -45% | -$253K |
|
3895
PUT
Krystal Biotech
KRYS
$10.7B
| $313K | ﹤0.01% |
2,700
-3,100
| -53% | -$378K |
|
3896
PUT
Blue Owl Capital
OBDC
$5.47B
| $313K | ﹤0.01% |
22,600
-15,400
| -41% | -$213K |
|
3897
CALL
Brookfield
BN
$104B
| $312K | ﹤0.01% |
15,450
-185,700
| -92% | -$4.18M |
|
3898
Hain Celestial
HAIN
$44.8M
| $312K | ﹤0.01% |
+30,129
| New | +$348K |
|
3899
CALL
PagerDuty
PD
$795M
| $312K | ﹤0.01% |
13,900
+1,400
| +11% | +$33.4K |
|
|
CEQP
3900
PUT
DELISTED
Crestwood Equity Partners LP
CEQP
| $312K | ﹤0.01% |
10,700
+7,500
| +234% | +$210K |
|
Similar funds
Simplex Trading's Q3 2023 Portfolio in Review
As of Q3 2023, Simplex Trading held 10,417 positions worth $127B, up 4.5% from $122B the previous quarter. Its ten largest holdings account for 44% of the portfolio.
Simplex Trading deployed $11.9B of net new capital in Q3 2023, opening 1,399 new positions and adding to 3,690 existing holdings. Its largest new stake was Amazon: 841,102 shares worth $107M.
By sector, the portfolio is most concentrated in Technology at 0.44% of assets, up from 0.41% a quarter earlier, followed by Consumer Discretionary and Healthcare.
On the sell side, the largest reduction was Netflix, an estimated $27.1M trimmed.
- Simplex Trading's largest Q3 2023 buy was Amazon: 841,102 shares worth $107M.
- Simplex Trading added most to SPDR Gold Trust in Q3 2023, an estimated $68.6M increase.
- Simplex Trading's biggest Q3 2023 reduction was Netflix, cutting an estimated $27.1M.
- Simplex Trading fully exited Qualcomm in Q3 2023, selling an estimated $24.6M.
- Simplex Trading's ten largest holdings make up 44% of its $127B portfolio in Q3 2023.
- Simplex Trading opened 1,399 new positions and closed 1,719 in Q3 2023.
- Simplex Trading's portfolio value rose 4.5% quarter-over-quarter to $127B.
Based on Simplex Trading's 13F filing for Q3 2023, filed 1 Nov 2023.