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 | |
|---|---|---|---|---|---|---|
4326
Gaotu Techedu
GOTU
$405M
| $334K | ﹤0.01% |
102,568
+12,387
| +14% | +$45K |
|
4327
PUT
MaxLinear
MXL
$5.19B
| $334K | ﹤0.01% |
20,800
-100
| -0.5% | -$1.57K |
|
|
EB
4328
CALL
DELISTED
Eventbrite
EB
| $333K | ﹤0.01% |
132,400
-246,000
| -65% | -$643K |
|
|
ONT
4329
Onterris Inc
ONT
$731M
| $333K | ﹤0.01% |
+12,158
| New | +$318K |
|
4330
CALL
Spire Global
SPIR
$408M
| $332K | ﹤0.01% |
30,300
+10,100
| +50% | +$104K |
|
4331
PUT
Vitesse Energy
VTS
$644M
| $332K | ﹤0.01% |
14,300
+3,200
| +29% | +$78.6K |
|
|
KRMN
4332
CALL
Karman Holdings
KRMN
$6.04B
| $332K | ﹤0.01% |
+4,600
| New | +$252K |
|
4333
CALL
AirSculpt Technologies
AIRS
$308M
| $331K | ﹤0.01% |
+41,300
| New | +$256K |
|
4334
Churchill Downs
CHDN
$6.17B
| $331K | ﹤0.01% |
3,422
-566
| -14% | -$58.2K |
|
|
CRESY
4335
CALL
Cresud
CRESY
$806M
| $331K | ﹤0.01% |
36,305
+18,859
| +108% | +$194K |
|
4336
CALL
Nuvectis Pharma
NVCT
$652M
| $331K | ﹤0.01% |
55,000
+47,200
| +605% | +$324K |
|
4337
PUT
Offerpad Solutions
OPAD
$18.5M
| $331K | ﹤0.01% |
+7,960
| New | +$218K |
|
4338
CALL
UMB Financial
UMBF
$11.3B
| $331K | ﹤0.01% |
2,800
+2,500
| +833% | +$288K |
|
|
SFIX
4339
Stitch Fix
SFIX
$567M
| $330K | ﹤0.01% |
+76,004
| New | +$375K |
|
4340
CALL
Tucows
TCX
$104M
| $330K | ﹤0.01% |
17,800
| – | – |
|
4341
Amkor Technology
AMKR
$10.6B
| $329K | ﹤0.01% |
11,611
-1,943
| -14% | -$46.8K |
|
|
DENN
4342
DELISTED
Denny's
DENN
| $329K | ﹤0.01% |
62,938
+30,017
| +91% | +$133K |
|
4343
CALL
NeoGenomics
NEO
$1.99B
| $329K | ﹤0.01% |
42,700
-2,800
| -6% | -$19.6K |
|
|
TGB
4344
CALL
Trekor Metals
TGB
$2.45B
| $329K | ﹤0.01% |
77,900
-42,400
| -35% | -$144K |
|
4345
Arvinas
ARVN
$530M
| $328K | ﹤0.01% |
38,530
-70,270
| -65% | -$533K |
|
4346
PUT
Fabrinet
FN
$14.9B
| $328K | ﹤0.01% |
900
-100
| -10% | -$32.9K |
|
4347
Ivanhoe Electric
IE
$1.38B
| $328K | ﹤0.01% |
26,198
+16,390
| +167% | +$162K |
|
4348
CALL
Louisiana-Pacific
LPX
$5.14B
| $328K | ﹤0.01% |
3,700
+400
| +12% | +$36.9K |
|
4349
Progress Software
PRGS
$1.75B
| $328K | ﹤0.01% |
7,477
-43,241
| -85% | -$1.99M |
|
4350
Toyota
TM
$228B
| $328K | ﹤0.01% |
+1,717
| New | +$324K |
|
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.