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 | |
|---|---|---|---|---|---|---|
5726
The Greenbrier Companies
GBX
$1.52B
| $102K | ﹤0.01% |
+2,225
| New | +$106K |
|
|
NOA
5727
CALL
North American Construction
NOA
$369M
| $102K | ﹤0.01% |
7,200
+4,900
| +213% | +$71.4K |
|
5728
Invesco National AMT-Free Municipal Bond ETF
PZA
$4.22B
| $102K | ﹤0.01% |
+4,435
| New | +$99.4K |
|
|
RC
5729
PUT
Ready Capital
RC
$258M
| $102K | ﹤0.01% |
26,600
+19,200
| +259% | +$81K |
|
5730
Rekor Systems
REKR
$85.8M
| $102K | ﹤0.01% |
65,253
-112,516
| -63% | -$142K |
|
5731
CALL
Sana Biotechnology
SANA
$871M
| $102K | ﹤0.01% |
28,900
-18,700
| -39% | -$67.6K |
|
5732
Compass Diversified
CODI
$758M
| $101K | ﹤0.01% |
15,302
-17,707
| -54% | -$122K |
|
5733
Dover
DOV
$27.6B
| $101K | ﹤0.01% |
+608
| New | +$109K |
|
5734
PUT
Editas Medicine
EDIT
$396M
| $101K | ﹤0.01% |
29,300
+4,600
| +19% | +$12.8K |
|
5735
PUT
Fossil Group
FOSL
$293M
| $101K | ﹤0.01% |
+39,400
| New | +$93K |
|
5736
PUT
James Hardie Industries
JHX
$15.3B
| $101K | ﹤0.01% |
5,300
| – | – |
|
|
FIRY
5737
PUT
Firy Inc
FIRY
$148M
| $101K | ﹤0.01% |
12,700
+12,400
| +4,133% | +$95.3K |
|
|
TECX
5738
PUT
Tectonic Therapeutic
TECX
$529M
| $101K | ﹤0.01% |
6,500
+5,600
| +622% | +$116K |
|
|
AIRO
5739
CALL
AIRO Group Holdings
AIRO
$212M
| $101K | ﹤0.01% |
+5,300
| New | +$116K |
|
|
AIRO
5740
AIRO Group Holdings
AIRO
$212M
| $101K | ﹤0.01% |
+5,305
| New | +$116K |
|
5741
CALL
BGSF Inc
BGSF
$59.5M
| $100K | ﹤0.01% |
14,100
+13,100
| +1,310% | +$85K |
|
5742
PUT
Blink Charging
BLNK
$74.3M
| $100K | ﹤0.01% |
61,500
+1,600
| +3% | +$1.78K |
|
|
BNC
5743
CEA Industries
BNC
$110M
| $100K | ﹤0.01% |
+12,895
| New | +$219K |
|
|
CTLP
5744
CALL
DELISTED
Cantaloupe
CTLP
| $100K | ﹤0.01% |
9,500
-21,700
| -70% | -$237K |
|
5745
CALL
Dynagas LNG Partners
DLNG
$132M
| $100K | ﹤0.01% |
28,500
+26,300
| +1,195% | +$95.7K |
|
5746
CALL
Frontdoor
FTDR
$5.1B
| $100K | ﹤0.01% |
1,500
+600
| +67% | +$36.5K |
|
5747
CALL
Fuel Tech
FTEK
$43.9M
| $100K | ﹤0.01% |
+33,500
| New | +$97.2K |
|
5748
CALL
Flotek Industries
FTK
$852M
| $100K | ﹤0.01% |
6,900
-27,400
| -80% | -$346K |
|
|
GRFS
5749
PUT
Grifois
GRFS
$5.36B
| $100K | ﹤0.01% |
10,100
-5,300
| -34% | -$53K |
|
5750
CALL
Hexcel
HXL
$7.79B
| $100K | ﹤0.01% |
1,600
-1,400
| -47% | -$86K |
|
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.