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 | |
|---|---|---|---|---|---|---|
4051
CALL
Petco
WOOF
$794M
| $420K | ﹤0.01% |
108,700
+53,500
| +97% | +$179K |
|
4052
PUT
Targa Resources
TRGP
$57.3B
| $418K | ﹤0.01% |
2,500
-10,500
| -81% | -$1.75M |
|
4053
PUT
Dianthus Therapeutics
DNTH
$5.55B
| $417K | ﹤0.01% |
10,600
+5,600
| +112% | +$143K |
|
4054
Consolidated Edison
ED
$41.4B
| $417K | ﹤0.01% |
+4,149
| New | +$416K |
|
4055
CALL
Limbach Holdings
LMB
$818M
| $417K | ﹤0.01% |
4,300
+1,600
| +59% | +$193K |
|
4056
MoonLake Immunotherapeutics
MLTX
$1.58B
| $417K | ﹤0.01% |
+58,229
| New | +$3.03M |
|
4057
CALL
NETGEAR
NTGR
$620M
| $417K | ﹤0.01% |
12,900
+3,700
| +40% | +$101K |
|
|
VRNT
4058
PUT
DELISTED
Verint Systems
VRNT
| $417K | ﹤0.01% |
20,600
+17,500
| +565% | +$360K |
|
4059
CALL
Voyager Therapeutics
VYGR
$185M
| $417K | ﹤0.01% |
89,400
+85,500
| +2,192% | +$309K |
|
4060
CALL
Opko Health
OPK
$1.08B
| $416K | ﹤0.01% |
269,000
-273,100
| -50% | -$375K |
|
4061
PUT
Old Republic International
ORI
$10.9B
| $416K | ﹤0.01% |
9,800
| – | – |
|
4062
CALL
Rayonier
RYN
$6.6B
| $416K | ﹤0.01% |
16,466
-32,304
| -66% | -$775K |
|
4063
CALL
Arbe Robotics
ARBE
$76M
| $415K | ﹤0.01% |
251,800
+13,400
| +6% | +$19.5K |
|
4064
PUT
Energizer
ENR
$1.48B
| $415K | ﹤0.01% |
16,700
-1,500
| -8% | -$39.2K |
|
4065
PUT
loanDepot
LDI
$548M
| $415K | ﹤0.01% |
+135,500
| New | +$313K |
|
4066
PUT
Impinj
PI
$4.03B
| $415K | ﹤0.01% |
2,300
+1,100
| +92% | +$173K |
|
4067
CALL
Globe Life
GL
$13.9B
| $414K | ﹤0.01% |
2,900
-4,500
| -61% | -$610K |
|
4068
PUT
NewMarket
NEU
$7.13B
| $414K | ﹤0.01% |
500
+200
| +67% | +$154K |
|
4069
CALL
Park Hotels & Resorts
PK
$3.07B
| $414K | ﹤0.01% |
37,400
-27,700
| -43% | -$311K |
|
4070
CALL
Atlas Energy Solutions
AESI
$1.3B
| $413K | ﹤0.01% |
36,400
+19,100
| +110% | +$234K |
|
4071
Gevo
GEVO
$351M
| $413K | ﹤0.01% |
211,203
+61,670
| +41% | +$100K |
|
4072
PUT
Trex
TREX
$4.4B
| $413K | ﹤0.01% |
8,000
-26,500
| -77% | -$1.61M |
|
4073
PUT
Black Stone Minerals
BSM
$3.18B
| $412K | ﹤0.01% |
31,400
+20,500
| +188% | +$258K |
|
|
FLNA
4074
CALL
Filana Therapeutics
FLNA
$42.2M
| $412K | ﹤0.01% |
141,800
-42,200
| -23% | -$97K |
|
|
NMAX
4075
Newsmax Inc
NMAX
$998M
| $412K | ﹤0.01% |
33,249
+11,166
| +51% | +$151K |
|
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.