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 | |
|---|---|---|---|---|---|---|
2901
CALL
Kosmos Energy
KOS
$1.45B
| $1.17M | ﹤0.01% |
702,400
+399,100
| +132% | +$747K |
|
2902
CALL
Viper Energy
VNOM
$8.51B
| $1.17M | ﹤0.01% |
30,500
+20,300
| +199% | +$773K |
|
|
DFTX
2903
PUT
Definium Therapeutics
DFTX
$5.65B
| $1.16M | ﹤0.01% |
98,800
+26,500
| +37% | +$247K |
|
2904
ODDITY Tech
ODD
$755M
| $1.16M | ﹤0.01% |
18,696
-2,094
| -10% | -$136K |
|
|
GES
2905
DELISTED
Guess Inc
GES
| $1.16M | ﹤0.01% |
69,651
+30,556
| +78% | +$453K |
|
2906
PUT
Texas Roadhouse
TXRH
$13.2B
| $1.16M | ﹤0.01% |
7,000
-3,800
| -35% | -$670K |
|
2907
Jefferies Financial Group
JEF
$12.7B
| $1.16M | ﹤0.01% |
17,777
+16,867
| +1,854% | +$1.03M |
|
2908
Liberty Energy
LBRT
$2.78B
| $1.16M | ﹤0.01% |
+94,207
| New | +$1.09M |
|
2909
PUT
Ziff Davis
ZD
$1.94B
| $1.16M | ﹤0.01% |
30,500
+30,000
| +6,000% | +$1.05M |
|
2910
Cadiz
CDZI
$247M
| $1.16M | ﹤0.01% |
246,090
+105,616
| +75% | +$369K |
|
|
AMRZ
2911
PUT
Amrize Ltd
AMRZ
$27.5B
| $1.16M | ﹤0.01% |
+23,900
| New | +$1.22M |
|
2912
CALL
Larimar Therapeutics
LRMR
$398M
| $1.16M | ﹤0.01% |
358,600
+28,400
| +9% | +$106K |
|
2913
Digital Realty Trust
DLR
$71.2B
| $1.16M | ﹤0.01% |
+6,689
| New | +$1.14M |
|
2914
PUT
Asana
ASAN
$1.83B
| $1.16M | ﹤0.01% |
86,500
+8,500
| +11% | +$120K |
|
2915
PUT
Coty
COTY
$2.33B
| $1.15M | ﹤0.01% |
285,700
+274,900
| +2,545% | +$1.26M |
|
2916
CoreCivic
CXW
$3.09B
| $1.15M | ﹤0.01% |
56,744
+37,936
| +202% | +$786K |
|
2917
Stanley Black & Decker
SWK
$14.4B
| $1.15M | ﹤0.01% |
15,520
-16,250
| -51% | -$1.19M |
|
2918
Ardelyx
ARDX
$1.26B
| $1.15M | ﹤0.01% |
209,233
+79,552
| +61% | +$432K |
|
2919
CALL
Landstar System
LSTR
$6.52B
| $1.15M | ﹤0.01% |
9,400
+6,900
| +276% | +$916K |
|
2920
Bakkt Inc
BKKT
$333M
| $1.15M | ﹤0.01% |
+34,162
| New | +$470K |
|
2921
PUT
MasTec
MTZ
$25.6B
| $1.15M | ﹤0.01% |
5,400
+4,000
| +286% | +$732K |
|
2922
CALL
Finance of America Companies
FOA
$204M
| $1.15M | ﹤0.01% |
51,200
+40,900
| +397% | +$1.02M |
|
|
HNGE
2923
PUT
Hinge Health
HNGE
$5.88B
| $1.15M | ﹤0.01% |
23,400
-33,500
| -59% | -$1.75M |
|
2924
Sonoco
SON
$5.79B
| $1.15M | ﹤0.01% |
26,636
+3,947
| +17% | +$182K |
|
2925
PUT
Markel Group
MKL
$25.2B
| $1.15M | ﹤0.01% |
600
| – | – |
|
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.