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 | |
|---|---|---|---|---|---|---|
126
CALL
Reddit
RDDT
$32.9B
| $162M | 0.08% |
703,700
-58,700
| -8% | -$12M |
|
127
PUT
Direxion Daily Technology Bull 3x ETF
TECL
$5.62B
| $161M | 0.08% |
3,945,600
+372,000
| +10% | +$39.1M |
|
128
PUT
Berkshire Hathaway Class B
BRK.B
$1.05T
| $159M | 0.08% |
317,100
-83,500
| -21% | -$40.4M |
|
129
PUT
SoFi Technologies
SOFI
$22B
| $158M | 0.08% |
5,992,000
-2,027,700
| -25% | -$48.1M |
|
130
CALL
iShares MSCI Australia ETF
EWA
$1.35B
| $158M | 0.08% |
4,529,200
+516,600
| +13% | +$13.8M |
|
131
PUT
Morgan Stanley
MS
$343B
| $155M | 0.08% |
975,900
+38,100
| +4% | +$5.63M |
|
132
CALL
Carvana
CVNA
$45.6B
| $153M | 0.08% |
2,033,500
-690,500
| -25% | -$49.4M |
|
133
PUT
Vanguard S&P 500 ETF
VOO
$982B
| $153M | 0.08% |
332,400
-196,600
| -37% | -$116M |
|
134
PUT
ExxonMobil
XOM
$640B
| $153M | 0.08% |
1,354,600
-209,200
| -13% | -$23.3M |
|
135
PUT
Marvell Technology
MRVL
$192B
| $151M | 0.08% |
1,792,600
-125,500
| -7% | -$9.24M |
|
136
CALL
lululemon athletica
LULU
$12.9B
| $150M | 0.08% |
842,700
+555,200
| +193% | +$111M |
|
137
CALL
Direxion Daily S&P Oil & Gas Exp. & Prod. Bull 2X ETF
GUSH
$254M
| $149M | 0.08% |
5,099,700
+927,400
| +22% | +$21.9M |
|
|
138
iShares Russell 2000 ETF
IWM
$81.8B
| $149M | 0.08% |
617,585
+424,988
| +221% | +$97.5M |
|
|
NVO
139
CALL
Novo Nordisk
NVO
$213B
| $149M | 0.08% |
2,676,500
+1,756,000
| +191% | +$103M |
|
140
PUT
Marathon Digital Holdings
MARA
$4.75B
| $145M | 0.07% |
7,948,100
+3,671,300
| +86% | +$61.9M |
|
141
PUT
Wells Fargo
WFC
$262B
| $144M | 0.07% |
1,715,300
-734,400
| -30% | -$59.6M |
|
142
CALL
Arista Networks
ANET
$221B
| $144M | 0.07% |
986,500
-113,800
| -10% | -$14.7M |
|
|
143
PUT
lululemon athletica
LULU
$12.9B
| $140M | 0.07% |
789,100
+443,400
| +128% | +$88.8M |
|
|
NBIS
144
PUT
Nebius Group N.V.
NBIS
$57.6B
| $135M | 0.07% |
1,205,800
+738,800
| +158% | +$51.3M |
|
|
145
CALL
Direxion Daily Technology Bull 3x ETF
TECL
$5.62B
| $133M | 0.07% |
2,992,500
+97,900
| +3% | +$10.3M |
|
|
CRCL
146
PUT
Circle Internet Group
CRCL
$16.7B
| $132M | 0.07% |
994,000
+249,300
| +33% | +$39.4M |
|
147
PUT
Dell
DELL
$286B
| $130M | 0.07% |
915,600
+203,500
| +29% | +$26.4M |
|
148
PUT
IonQ
IONQ
$13.2B
| $129M | 0.07% |
2,100,100
+894,200
| +74% | +$42M |
|
149
CALL
Visa
V
$676B
| $129M | 0.07% |
377,600
-37,300
| -9% | -$12.9M |
|
150
PUT
Adobe
ADBE
$87.9B
| $128M | 0.07% |
361,500
+87,400
| +32% | +$31.4M |
|
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.