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 | |
|---|---|---|---|---|---|---|
6426
CALL
Penske Automotive Group
PAG
$14.7B
| $52K | ﹤0.01% |
300
+100
| +50% | +$17.8K |
|
6427
PUT
Paymentus
PAY
$4.62B
| $52K | ﹤0.01% |
1,700
+1,400
| +467% | +$46.3K |
|
6428
QuinStreet
QNST
$927M
| $52K | ﹤0.01% |
3,368
-5,894
| -64% | -$93.6K |
|
6429
CALL
Seanergy Maritime Holdings
SHIP
$349M
| $52K | ﹤0.01% |
6,400
-17,500
| -73% | -$133K |
|
|
BNKK
6430
PUT
Bonk Inc
BNKK
$7.7M
| $52K | ﹤0.01% |
+2,586
| New | +$47.2K |
|
|
SIFY
6431
Sify Technologies
SIFY
$1.01B
| $52K | ﹤0.01% |
+3,870
| New | +$32.8K |
|
6432
PUT
Spero Therapeutics
SPRO
$68.9M
| $52K | ﹤0.01% |
28,100
-140,700
| -83% | -$309K |
|
6433
Upland Software
UPLD
$13.3M
| $52K | ﹤0.01% |
2,236
+404
| +22% | +$9.19K |
|
6434
PUT
West Pharmaceutical
WST
$23.7B
| $52K | ﹤0.01% |
200
-3,200
| -94% | -$778K |
|
6435
PUT
Wolverine World Wide
WWW
$1.68B
| $52K | ﹤0.01% |
1,900
-2,200
| -54% | -$57.9K |
|
6436
ProFrac Holding
ACDC
$653M
| $51K | ﹤0.01% |
+13,968
| New | +$76.9K |
|
6437
PUT
BlueLinx
BXC
$430M
| $51K | ﹤0.01% |
700
+500
| +250% | +$39.4K |
|
6438
PUT
Designer Brands
DBI
$315M
| $51K | ﹤0.01% |
14,500
-6,100
| -30% | -$21.1K |
|
6439
CALL
Donnelley Financial Solutions
DFIN
$1.28B
| $51K | ﹤0.01% |
+1,000
| New | +$57K |
|
|
LKFT
6440
PUT
Lakefront Biotherapeutics American Depositary Shares
LKFT
$1.82B
| $51K | ﹤0.01% |
1,500
+100
| +7% | +$3.2K |
|
6441
CALL
Navigator Holdings
NVGS
$1.35B
| $51K | ﹤0.01% |
3,300
+3,200
| +3,200% | +$51.1K |
|
|
6442
PUT
Navigator Holdings
NVGS
$1.35B
| $51K | ﹤0.01% |
3,300
+2,800
| +560% | +$44.7K |
|
6443
SIGA Technologies
SIGA
$240M
| $51K | ﹤0.01% |
5,682
+3,366
| +145% | +$26.9K |
|
6444
iShares MSCI Global Silver and Metals Miners ETF
SLVP
$768M
| $51K | ﹤0.01% |
1,866
+33
| +2% | +$693 |
|
6445
CALL
Shattuck Labs
STTK
$646M
| $51K | ﹤0.01% |
+21,600
| New | +$26.4K |
|
6446
CALL
Tenaya Therapeutics
TNYA
$160M
| $51K | ﹤0.01% |
31,900
+20,300
| +175% | +$20.4K |
|
6447
Procure Space ETF
UFO
$599M
| $51K | ﹤0.01% |
1,442
+1,141
| +379% | +$36.4K |
|
|
SFD
6448
PUT
Smithfield Foods
SFD
$10.8B
| $51K | ﹤0.01% |
+2,200
| New | +$53.8K |
|
|
ALMU
6449
Aeluma Inc
ALMU
$276M
| $51K | ﹤0.01% |
+3,211
| New | +$60.1K |
|
6450
CALL
America Movil
AMX
$74.6B
| $50K | ﹤0.01% |
2,400
-1,400
| -37% | -$26.7K |
|
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.