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 | |
|---|---|---|---|---|---|---|
5776
PUT
Adtran
ADTN
$689M
| $97K | ﹤0.01% |
10,400
+9,600
| +1,200% | +$89.4K |
|
|
CGAU
5777
PUT
Centerra Gold
CGAU
$3.36B
| $97K | ﹤0.01% |
9,100
-3,600
| -28% | -$28.7K |
|
5778
PUT
Embecta
EMBC
$216M
| $97K | ﹤0.01% |
6,900
-4,700
| -41% | -$59.5K |
|
5779
ImmunityBio
IBRX
$7.51B
| $97K | ﹤0.01% |
39,490
-23,285
| -37% | -$60K |
|
|
MREO
5780
CALL
Mereo BioPharma
MREO
$54.7M
| $97K | ﹤0.01% |
47,200
-152,000
| -76% | -$280K |
|
5781
CALL
One Stop Systems
OSS
$303M
| $97K | ﹤0.01% |
18,100
+15,400
| +570% | +$84.3K |
|
5782
iShares Mortgage Real Estate ETF
REM
$539M
| $97K | ﹤0.01% |
+4,457
| New | +$99.3K |
|
5783
Schneider National
SNDR
$6.26B
| $97K | ﹤0.01% |
4,623
-61,868
| -93% | -$1.51M |
|
5784
Upbound Group
UPBD
$1.13B
| $97K | ﹤0.01% |
+4,112
| New | +$102K |
|
5785
XPEL
XPEL
$1.22B
| $97K | ﹤0.01% |
+2,949
| New | +$105K |
|
5786
PUT
Bain Capital Specialty
BCSF
$806M
| $96K | ﹤0.01% |
6,800
+4,700
| +224% | +$71.3K |
|
5787
CALL
Capital City Bank Group
CCBG
$888M
| $96K | ﹤0.01% |
+2,300
| New | +$95.7K |
|
5788
Coherus Oncology
CHRS
$217M
| $96K | ﹤0.01% |
58,823
+56,843
| +2,871% | +$63.2K |
|
5789
Camping World
CWH
$393M
| $96K | ﹤0.01% |
+6,101
| New | +$104K |
|
5790
CALL
Ducommun
DCO
$2.7B
| $96K | ﹤0.01% |
+1,000
| New | +$90.4K |
|
5791
CALL
LG Display
LPL
$3B
| $96K | ﹤0.01% |
+18,500
| New | +$76.9K |
|
5792
Reinsurance Group of America
RGA
$15.5B
| $96K | ﹤0.01% |
504
+222
| +79% | +$42.5K |
|
|
LINE
5793
PUT
Lineage Inc
LINE
$9.65B
| $96K | ﹤0.01% |
2,500
-4,500
| -64% | -$187K |
|
5794
CALL
Annovis Bio
ANVS
$74.4M
| $95K | ﹤0.01% |
46,200
-3,900
| -8% | -$9.75K |
|
5795
A2Z Smart Technologies
AZ
$274M
| $95K | ﹤0.01% |
11,992
-52,761
| -81% | -$500K |
|
5796
Cabot Corp
CBT
$4.54B
| $95K | ﹤0.01% |
1,260
+952
| +309% | +$74.3K |
|
5797
CALL
Carlyle Secured Lending
CGBD
$694M
| $95K | ﹤0.01% |
7,600
+300
| +4% | +$4.12K |
|
|
EU
5798
PUT
enCore Energy
EU
$212M
| $95K | ﹤0.01% |
29,900
+21,500
| +256% | +$57.9K |
|
5799
CALL
National Beverage
FIZZ
$2.96B
| $95K | ﹤0.01% |
2,600
+2,000
| +333% | +$86.6K |
|
5800
Grocery Outlet
GO
$909M
| $95K | ﹤0.01% |
+5,935
| New | +$94.8K |
|
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.