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 | |
|---|---|---|---|---|---|---|
7701
PUT
Immunic
IMUX
$186M
| $13K | ﹤0.01% |
+1,500
| New | +$13.2K |
|
7702
PUT
Kodiak Sciences
KOD
$2.62B
| $13K | ﹤0.01% |
+800
| New | +$6.89K |
|
7703
Merchants Bancorp
MBIN
$2.21B
| $13K | ﹤0.01% |
417
+378
| +969% | +$12.4K |
|
|
SUIG
7704
PUT
Sui Group Holdings
SUIG
$72.8M
| $13K | ﹤0.01% |
+3,400
| New | +$15.4K |
|
7705
PUT
Mitek Systems
MITK
$778M
| $13K | ﹤0.01% |
1,400
-1,100
| -44% | -$10.8K |
|
7706
Morningstar
MORN
$7.01B
| $13K | ﹤0.01% |
+60
| New | +$16K |
|
7707
CALL
Nomura Holdings
NMR
$28.4B
| $13K | ﹤0.01% |
1,900
-2,500
| -57% | -$17.6K |
|
|
7708
PUT
Nomura Holdings
NMR
$28.4B
| $13K | ﹤0.01% |
1,900
| – | – |
|
|
NSA
7709
DELISTED
National Storage Affiliates Trust
NSA
| $13K | ﹤0.01% |
+461
| New | +$14.4K |
|
7710
Ocugen
OCGN
$430M
| $13K | ﹤0.01% |
8,202
-30,981
| -79% | -$34.3K |
|
7711
Protolabs
PRLB
$1.84B
| $13K | ﹤0.01% |
+267
| New | +$12.2K |
|
7712
CALL
ProPetro Holding
PUMP
$1.35B
| $13K | ﹤0.01% |
2,500
-600
| -19% | -$3.18K |
|
7713
PUT
Qualys
QLYS
$4.82B
| $13K | ﹤0.01% |
100
-100
| -50% | -$13.6K |
|
7714
PUT
Quad
QUAD
$444M
| $13K | ﹤0.01% |
2,100
+100
| +5% | +$616 |
|
7715
RELX
RELX
$62.9B
| $13K | ﹤0.01% |
+282
| New | +$13.9K |
|
7716
CALL
RLI Corp
RLI
$5.87B
| $13K | ﹤0.01% |
200
| – | – |
|
7717
CALL
Rackspace Technology
RXT
$967M
| $13K | ﹤0.01% |
9,600
-14,100
| -59% | -$18.9K |
|
7718
iShares 0-3 Month Treasury Bond ETF
SGOV
$99.3B
| $13K | ﹤0.01% |
+131
| New | +$13.2K |
|
|
BNKK
7719
Bonk Inc
BNKK
$8.96M
| $13K | ﹤0.01% |
+1,447
| New | +$26.4K |
|
7720
CALL
Stock Yards Bancorp
SYBT
$2.42B
| $13K | ﹤0.01% |
+200
| New | +$15.4K |
|
7721
Tactile Systems Technology
TCMD
$630M
| $13K | ﹤0.01% |
991
-21
| -2% | -$253 |
|
7722
Turkcell
TKC
$4.79B
| $13K | ﹤0.01% |
+2,176
| New | +$12.7K |
|
7723
PUT
Twin Disc
TWIN
$336M
| $13K | ﹤0.01% |
+1,000
| New | +$10.8K |
|
7724
PUT
Ternium
TX
$9.26B
| $13K | ﹤0.01% |
400
-900
| -69% | -$29.5K |
|
7725
CALL
United States Lime & Minerals
USLM
$3.2B
| $13K | ﹤0.01% |
+100
| New | +$11.5K |
|
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.