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 | |
|---|---|---|---|---|---|---|
4451
CALL
Jacobs Solutions
J
$16B
| $301K | ﹤0.01% |
8,600
-1,700
| -17% | -$244K |
|
4452
CALL
Lear
LEA
$7.39B
| $301K | ﹤0.01% |
3,000
-5,800
| -66% | -$602K |
|
4453
CALL
SiTime
SITM
$13.8B
| $301K | ﹤0.01% |
1,000
-700
| -41% | -$162K |
|
4454
Champion Homes
SKY
$4.41B
| $301K | ﹤0.01% |
+3,945
| New | +$279K |
|
4455
CALL
Tecnoglass
TGLS
$1.99B
| $301K | ﹤0.01% |
4,500
+600
| +15% | +$44.3K |
|
4456
PUT
Tandem Diabetes Care
TNDM
$1.27B
| $301K | ﹤0.01% |
24,800
+9,900
| +66% | +$134K |
|
4457
CALL
CubeSmart
CUBE
$9.61B
| $300K | ﹤0.01% |
7,400
-24,800
| -77% | -$1.01M |
|
4458
PUT
Hess Midstream
HESM
$5.19B
| $300K | ﹤0.01% |
8,700
+6,700
| +335% | +$266K |
|
4459
CALL
Neonode
NEON
$12.6M
| $300K | ﹤0.01% |
86,100
+80,300
| +1,384% | +$1.48M |
|
4460
PUT
XPEL
XPEL
$1.22B
| $300K | ﹤0.01% |
+9,100
| New | +$323K |
|
|
TXNM
4461
TXNM Energy Inc
TXNM
$6.39B
| $300K | ﹤0.01% |
5,322
+1,659
| +45% | +$94.1K |
|
4462
ARK Blockchain & Fintech Innovation ETF
ARKF
$731M
| $299K | ﹤0.01% |
5,268
-14,358
| -73% | -$772K |
|
4463
Skywest
SKYW
$4.35B
| $299K | ﹤0.01% |
2,978
+773
| +35% | +$86.3K |
|
4464
PUT
Xponential Fitness
XPOF
$286M
| $299K | ﹤0.01% |
38,400
-9,200
| -19% | -$83.9K |
|
4465
CALL
Critical Metals Corp
CRML
$754M
| $299K | ﹤0.01% |
+48,100
| New | +$246K |
|
4466
Alector
ALEC
$169M
| $298K | ﹤0.01% |
+100,944
| New | +$222K |
|
4467
Ball Corp
BALL
$17.5B
| $298K | ﹤0.01% |
+5,925
| New | +$320K |
|
4468
CALL
CapForce IBD 50 ETF
FFTY
$78.8M
| $298K | ﹤0.01% |
+8,000
| New | +$277K |
|
4469
CALL
LivePerson
LPSN
$22M
| $298K | ﹤0.01% |
34,153
-100
| -0.3% | -$1.41K |
|
4470
Allot
ALLT
$362M
| $297K | ﹤0.01% |
28,140
-88,074
| -76% | -$747K |
|
4471
PUT
VanEck Energy Income ETF
EINC
$77.6M
| $297K | ﹤0.01% |
10,500
-8,600
| -45% | -$831K |
|
4472
PUT
Zebra Technologies
ZBRA
$13.5B
| $297K | ﹤0.01% |
1,000
+200
| +25% | +$63.9K |
|
4473
Kopin
KOPN
$586M
| $296K | ﹤0.01% |
121,833
+672
| +0.6% | +$1.37K |
|
4474
Revolve Group
RVLV
$1.85B
| $296K | ﹤0.01% |
13,909
+13,322
| +2,270% | +$291K |
|
4475
Sigma Lithium
SGML
$1.05B
| $296K | ﹤0.01% |
+46,323
| New | +$279K |
|
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.