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 | |
|---|---|---|---|---|---|---|
3501
CALL
Resideo Technologies
REZI
$5.55B
| $660K | ﹤0.01% |
15,300
+12,100
| +378% | +$378K |
|
3502
monday.com
MNDY
$3.68B
| $659K | ﹤0.01% |
3,407
-5,827
| -63% | -$1.34M |
|
3503
CALL
NET Power
NPWR
$126M
| $659K | ﹤0.01% |
219,200
-14,900
| -6% | -$39.8K |
|
3504
PUT
Mohawk Industries
MHK
$7.14B
| $657K | ﹤0.01% |
5,100
+4,500
| +750% | +$557K |
|
3505
CALL
Vipshop
VIPS
$7.13B
| $657K | ﹤0.01% |
33,500
-35,400
| -51% | -$587K |
|
|
GRAL
3506
PUT
GRAIL Inc
GRAL
$2.76B
| $656K | ﹤0.01% |
11,100
-4,500
| -29% | -$172K |
|
3507
Direxion Daily Financial Bear 3x ETF
FAZ
$82M
| $655K | ﹤0.01% |
16,207
+11,523
| +246% | +$493K |
|
3508
Appian
APPN
$2.01B
| $654K | ﹤0.01% |
21,419
+9,711
| +83% | +$292K |
|
3509
Fluor
FLR
$6.89B
| $653K | ﹤0.01% |
15,523
-63,295
| -80% | -$2.91M |
|
|
GRRR
3510
PUT
Gorilla Technology Group
GRRR
$323M
| $653K | ﹤0.01% |
35,400
+3,400
| +11% | +$62.5K |
|
3511
Monolithic Power Systems
MPWR
$63B
| $653K | ﹤0.01% |
710
+370
| +109% | +$300K |
|
|
NAKA
3512
CALL
Nakamoto Inc
NAKA
$78.7M
| $652K | ﹤0.01% |
+15,240
| New | +$4.83M |
|
3513
CALL
Xenon Pharmaceuticals
XENE
$6.28B
| $650K | ﹤0.01% |
16,200
-800
| -5% | -$28.2K |
|
3514
Digital Turbine
APPS
$1.02B
| $649K | ﹤0.01% |
101,512
+82,934
| +446% | +$412K |
|
|
LINE
3515
CALL
Lineage Inc
LINE
$9.7B
| $649K | ﹤0.01% |
16,800
+14,000
| +500% | +$582K |
|
3516
CALL
Atmos Energy
ATO
$29.9B
| $648K | ﹤0.01% |
3,800
+2,300
| +153% | +$371K |
|
3517
CALL
CryoPort
CYRX
$765M
| $648K | ﹤0.01% |
68,400
+22,800
| +50% | +$192K |
|
3518
EVgo
EVGO
$230M
| $648K | ﹤0.01% |
137,057
+81,109
| +145% | +$314K |
|
3519
PUT
Kimco Realty
KIM
$17.7B
| $648K | ﹤0.01% |
29,700
+100
| +0.3% | +$2.17K |
|
3520
PUT
Prime Medicine
PRME
$558M
| $648K | ﹤0.01% |
117,100
-71,100
| -38% | -$289K |
|
|
MRP
3521
CALL
Millrose Properties Inc
MRP
$4.75B
| $648K | ﹤0.01% |
19,300
-2,000
| -9% | -$64.6K |
|
3522
PUT
Liberty Global Class C
LBTYK
$3.4B
| $646K | ﹤0.01% |
56,400
+300
| +0.5% | +$3.36K |
|
3523
CALL
XP
XP
$8.68B
| $646K | ﹤0.01% |
34,400
-32,900
| -49% | -$590K |
|
3524
CALL
Grindr
GRND
$2.95B
| $644K | ﹤0.01% |
42,900
-30,300
| -41% | -$531K |
|
3525
Star Bulk Carriers
SBLK
$3.12B
| $644K | ﹤0.01% |
34,658
+25,498
| +278% | +$480K |
|
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.