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 | |
|---|---|---|---|---|---|---|
1976
CALL
The RealReal
REAL
$1.34B
| $2.84M | ﹤0.01% |
267,300
+179,800
| +205% | +$1.33M |
|
1977
CALL
Listed Funds Trust Roundhill Magnificent Seven ETF
MAGS
$3.91B
| $2.84M | ﹤0.01% |
49,800
-51,900
| -51% | -$3.1M |
|
1978
Resideo Technologies
REZI
$5.23B
| $2.83M | ﹤0.01% |
+65,677
| New | +$2.05M |
|
1979
CALL
Welltower
WELL
$178B
| $2.83M | ﹤0.01% |
15,900
-900
| -5% | -$148K |
|
1980
Cleveland-Cliffs
CLF
$6.81B
| $2.83M | ﹤0.01% |
232,105
+171,782
| +285% | +$1.81M |
|
1981
PUT
Equity Residential
EQR
$25.4B
| $2.83M | ﹤0.01% |
43,700
+24,500
| +128% | +$1.6M |
|
1982
CALL
Huntington Ingalls Industries
HII
$11.3B
| $2.82M | ﹤0.01% |
9,800
+7,000
| +250% | +$1.87M |
|
1983
Polaris
PII
$4.15B
| $2.82M | ﹤0.01% |
48,509
+7,935
| +20% | +$428K |
|
1984
CALL
Old Dominion Freight Line
ODFL
$48.5B
| $2.81M | ﹤0.01% |
20,000
-300
| -1% | -$45.9K |
|
1985
United Natural Foods
UNFI
$3.01B
| $2.81M | ﹤0.01% |
74,827
+20,301
| +37% | +$557K |
|
1986
ProShares UltraPro Short S&P 500
SPXU
$436M
| $2.8M | ﹤0.01% |
+51,901
| New | +$3.17M |
|
1987
Intuitive Machines
LUNR
$2.07B
| $2.8M | ﹤0.01% |
266,395
+70,962
| +36% | +$720K |
|
1988
PUT
Natera
NTRA
$37.5B
| $2.8M | ﹤0.01% |
17,400
+13,000
| +295% | +$2.06M |
|
|
OPRA
1989
CALL
Opera Ltd
OPRA
$1.65B
| $2.79M | ﹤0.01% |
135,300
+97,100
| +254% | +$1.73M |
|
1990
CALL
Eldorado Gold
EGO
$8.31B
| $2.79M | ﹤0.01% |
96,600
+38,000
| +65% | +$895K |
|
1991
Zscaler
ZS
$23B
| $2.79M | ﹤0.01% |
9,312
-676
| -7% | -$193K |
|
|
SII
1992
CALL
Sprott
SII
$2.65B
| $2.79M | ﹤0.01% |
33,500
-15,500
| -32% | -$1.08M |
|
1993
PUT
Cal-Maine
CALM
$4.28B
| $2.77M | ﹤0.01% |
29,500
+10,600
| +56% | +$1.13M |
|
1994
CALL
Ivanhoe Electric
IE
$1.43B
| $2.77M | ﹤0.01% |
221,000
+198,500
| +882% | +$1.96M |
|
1995
CALL
Corteva
CTVA
$59.7B
| $2.77M | ﹤0.01% |
41,000
+28,900
| +239% | +$2.09M |
|
1996
CALL
Dycom Industries
DY
$12.9B
| $2.77M | ﹤0.01% |
9,500
+4,900
| +107% | +$1.29M |
|
|
VTLE
1997
PUT
DELISTED
Vital Energy
VTLE
| $2.77M | ﹤0.01% |
163,900
+91,400
| +126% | +$1.54M |
|
1998
PUT
XP
XP
$8.62B
| $2.77M | ﹤0.01% |
147,300
-23,000
| -14% | -$412K |
|
1999
TD Synnex
SNX
$19.4B
| $2.76M | ﹤0.01% |
16,881
+16,324
| +2,931% | +$2.41M |
|
2000
CALL
Iron Mountain
IRM
$38.2B
| $2.76M | ﹤0.01% |
27,100
+9,600
| +55% | +$925K |
|
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.