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 | |
|---|---|---|---|---|---|---|
3851
Sun Communities
SUI
$15.3B
| $489K | ﹤0.01% |
3,793
+2,233
| +143% | +$282K |
|
3852
CALL
Bio-Techne
TECH
$11.2B
| $489K | ﹤0.01% |
8,800
-10,700
| -55% | -$573K |
|
3853
PUT
CBRE Group
CBRE
$43.1B
| $488K | ﹤0.01% |
3,100
+1,900
| +158% | +$294K |
|
3854
PUT
Ingredion
INGR
$6.48B
| $488K | ﹤0.01% |
4,000
+3,900
| +3,900% | +$503K |
|
3855
CALL
Northern Oil and Gas
NOG
$2.16B
| $488K | ﹤0.01% |
19,700
-23,900
| -55% | -$634K |
|
3856
Tradr TSLA Bear Daily ETF
TSLQ
$147M
| $488K | ﹤0.01% |
20,245
+16,168
| +397% | +$720K |
|
|
KDK
3857
CALL
Kodiak AI
KDK
$794M
| $488K | ﹤0.01% |
71,400
+71,100
| +23,700% | +$787K |
|
3858
PUT
BellRing Brands
BRBR
$1.59B
| $487K | ﹤0.01% |
13,400
-17,500
| -57% | -$791K |
|
3859
CALL
Genmab
GMAB
$17.8B
| $487K | ﹤0.01% |
15,900
-200
| -1% | -$4.87K |
|
|
JHG
3860
DELISTED
Janus Henderson
JHG
| $487K | ﹤0.01% |
+10,957
| New | +$473K |
|
|
SVM
3861
PUT
Silvercorp Metals
SVM
$2.08B
| $487K | ﹤0.01% |
77,200
+9,200
| +14% | +$45K |
|
3862
Cars.com
CARS
$705M
| $486K | ﹤0.01% |
39,788
-5,788
| -13% | -$74.3K |
|
3863
PUT
Globe Life
GL
$13.9B
| $486K | ﹤0.01% |
3,400
| – | – |
|
3864
CALL
Fiverr
FVRR
$417M
| $485K | ﹤0.01% |
19,900
+200
| +1% | +$4.9K |
|
|
DFTX
3865
Definium Therapeutics
DFTX
$5.57B
| $485K | ﹤0.01% |
41,165
-46,786
| -53% | -$436K |
|
3866
Sinclair Inc
SBGI
$1.02B
| $485K | ﹤0.01% |
32,180
+8,382
| +35% | +$120K |
|
|
THS
3867
CALL
DELISTED
Treehouse Foods
THS
| $485K | ﹤0.01% |
24,000
+19,700
| +458% | +$374K |
|
3868
CALL
Allegro MicroSystems
ALGM
$8.29B
| $484K | ﹤0.01% |
16,600
-26,100
| -61% | -$844K |
|
|
3869
PUT
Allegro MicroSystems
ALGM
$8.29B
| $484K | ﹤0.01% |
16,600
-150,500
| -90% | -$4.87M |
|
3870
CALL
Ardmore Shipping
ASC
$669M
| $484K | ﹤0.01% |
40,800
-5,600
| -12% | -$62.7K |
|
3871
PUT
EyePoint Inc
EYPT
$1B
| $484K | ﹤0.01% |
34,000
-83,400
| -71% | -$960K |
|
3872
CALL
HEICO Corp Class A
HEI.A
$36.8B
| $484K | ﹤0.01% |
1,500
+200
| +15% | +$50K |
|
3873
Alight
ALIT
$523M
| $483K | ﹤0.01% |
7,419
-2,393
| -24% | -$211K |
|
3874
PUT
Vanguard Total Bond Market
BND
$158B
| $483K | ﹤0.01% |
6,500
+5,700
| +713% | +$420K |
|
3875
PUT
SEALSQ Corp
LAES
$521M
| $483K | ﹤0.01% |
129,400
-59,900
| -32% | -$194K |
|
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.