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 | |
|---|---|---|---|---|---|---|
|
SMLR
2976
PUT
DELISTED
Semler Scientific
SMLR
| $1.08M | ﹤0.01% |
35,900
+7,500
| +26% | +$258K |
|
2977
CALL
Blackstone Secured Lending
BXSL
$5.35B
| $1.08M | ﹤0.01% |
41,300
+4,600
| +13% | +$138K |
|
2978
CALL
Invesco DB Base Metals Fund
DBB
$308M
| $1.07M | ﹤0.01% |
64,800
+44,000
| +212% | +$866K |
|
2979
2x Long VIX Futures ETF
UVIX
$271M
| $1.07M | ﹤0.01% |
5,404
+5,284
| +4,403% | +$1.58M |
|
2980
PUT
Becton Dickinson
BDX
$43.8B
| $1.07M | ﹤0.01% |
5,700
-11,900
| -68% | -$2.21M |
|
2981
PUT
F5
FFIV
$23B
| $1.07M | ﹤0.01% |
3,300
+1,400
| +74% | +$438K |
|
2982
Republic Services
RSG
$66.7B
| $1.06M | ﹤0.01% |
+4,622
| New | +$1.08M |
|
|
HOUS
2983
CALL
DELISTED
Anywhere Real Estate
HOUS
| $1.06M | ﹤0.01% |
100,000
+99,700
| +33,233% | +$586K |
|
2984
CALL
CytomX Therapeutics
CTMX
$708M
| $1.06M | ﹤0.01% |
331,900
-34,900
| -10% | -$78.6K |
|
2985
ZIM Integrated Shipping Services
ZIM
$2.96B
| $1.06M | ﹤0.01% |
78,122
-19,817
| -20% | -$301K |
|
2986
CALL
Copa Holdings
CPA
$5.65B
| $1.06M | ﹤0.01% |
8,900
+1,300
| +17% | +$149K |
|
2987
Evergy
EVRG
$19.8B
| $1.06M | ﹤0.01% |
13,913
+11,773
| +550% | +$839K |
|
2988
PUT
Chemours
CC
$2.55B
| $1.05M | ﹤0.01% |
66,600
-4,800
| -7% | -$69.6K |
|
2989
CALL
Dimensional US Core Equity Market ETF
DFAU
$12.3B
| $1.05M | ﹤0.01% |
20,800
+20,000
| +2,500% | +$881K |
|
2990
Sundial Growers
SNDL
$351M
| $1.05M | ﹤0.01% |
393,556
+114,056
| +41% | +$229K |
|
2991
Argan
AGX
$7.61B
| $1.05M | ﹤0.01% |
+3,901
| New | +$894K |
|
|
DEFT
2992
CALL
Defi Technologies
DEFT
$166M
| $1.05M | ﹤0.01% |
+498,300
| New | +$1.29M |
|
2993
CALL
Loar Holdings
LOAR
$6.72B
| $1.05M | ﹤0.01% |
13,100
+11,500
| +719% | +$865K |
|
2994
United States Copper Index Fund
CPER
$750M
| $1.05M | ﹤0.01% |
+34,905
| New | +$1.05M |
|
2995
Portillo's
PTLO
$338M
| $1.04M | ﹤0.01% |
162,029
+153,148
| +1,724% | +$1.29M |
|
2996
CALL
Solventum
SOLV
$13.9B
| $1.04M | ﹤0.01% |
14,300
+3,600
| +34% | +$264K |
|
|
OPRA
2997
PUT
Opera Ltd
OPRA
$1.69B
| $1.04M | ﹤0.01% |
50,500
+40,400
| +400% | +$722K |
|
2998
CALL
Protagonist Therapeutics
PTGX
$8.72B
| $1.04M | ﹤0.01% |
15,700
+12,400
| +376% | +$705K |
|
2999
PUT
Weibo
WB
$1.92B
| $1.04M | ﹤0.01% |
84,100
-40,000
| -32% | -$438K |
|
3000
PennyMac Financial
PFSI
$4.39B
| $1.04M | ﹤0.01% |
8,404
-11,794
| -58% | -$1.28M |
|
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.