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 | |
|---|---|---|---|---|---|---|
|
MAXN
4751
PUT
DELISTED
Maxeon Solar Technologies
MAXN
| $233K | ﹤0.01% |
69,800
-200
| -0.3% | -$781 |
|
4752
Opko Health
OPK
$1.02B
| $233K | ﹤0.01% |
+150,566
| New | +$207K |
|
|
UDMY
4753
CALL
DELISTED
Udemy
UDMY
| $233K | ﹤0.01% |
33,300
+30,000
| +909% | +$210K |
|
4754
PUT
Solventum
SOLV
$15.3B
| $233K | ﹤0.01% |
3,200
-2,600
| -45% | -$191K |
|
|
SRTA
4755
Strata Critical Medical Inc
SRTA
$421M
| $232K | ﹤0.01% |
46,033
-387
| -0.8% | -$1.71K |
|
4756
CALL
Celcuity
CELC
$4.06B
| $232K | ﹤0.01% |
4,700
+4,500
| +2,250% | +$180K |
|
4757
Telos
TLS
$331M
| $232K | ﹤0.01% |
+33,920
| New | +$162K |
|
4758
CALL
Travel + Leisure Co
TNL
$4.76B
| $232K | ﹤0.01% |
3,900
+1,100
| +39% | +$66K |
|
4759
CALL
VSE Corp
VSEC
$5.19B
| $232K | ﹤0.01% |
1,400
| – | – |
|
|
WCC
4760
CALL
WESCO International
WCC
$15.1B
| $232K | ﹤0.01% |
1,100
-2,900
| -73% | -$609K |
|
4761
Amdocs
DOX
$6.03B
| $231K | ﹤0.01% |
+2,821
| New | +$245K |
|
|
DPRO
4762
PUT
Draganfly
DPRO
$140M
| $231K | ﹤0.01% |
+28,400
| New | +$141K |
|
4763
Illumina
ILMN
$29.5B
| $231K | ﹤0.01% |
+2,438
| New | +$242K |
|
4764
Lightbridge
LTBR
$251M
| $231K | ﹤0.01% |
+10,929
| New | +$164K |
|
4765
CALL
M/I Homes
MHO
$3.95B
| $231K | ﹤0.01% |
1,600
+300
| +23% | +$40.6K |
|
|
ATYR
4766
PUT
aTyr Pharma
ATYR
$47.4M
| $231K | ﹤0.01% |
320,500
+262,800
| +455% | +$1.19M |
|
4767
Bausch + Lomb
BLCO
$5.78B
| $230K | ﹤0.01% |
15,326
-2,753
| -15% | -$39.7K |
|
4768
BuzzFeed
BZFD
$99M
| $230K | ﹤0.01% |
135,354
+36,354
| +37% | +$74.1K |
|
4769
Freedom Holding
FRHC
$9.44B
| $230K | ﹤0.01% |
1,338
-626
| -32% | -$106K |
|
4770
nCino
NCNO
$2.06B
| $230K | ﹤0.01% |
8,488
-5,009
| -37% | -$146K |
|
|
PSTL
4771
CALL
Postal Realty Trust
PSTL
$703M
| $230K | ﹤0.01% |
14,700
+6,300
| +75% | +$95.4K |
|
|
SGMO
4772
PUT
DELISTED
SANGAMO THERAPEUTICS INC
SGMO
| $230K | ﹤0.01% |
342,000
+63,200
| +23% | +$34.1K |
|
4773
Cimpress
CMPR
$2.37B
| $229K | ﹤0.01% |
3,638
-5,591
| -61% | -$313K |
|
4774
GSI Technology
GSIT
$201M
| $229K | ﹤0.01% |
62,339
+42,393
| +213% | +$160K |
|
4775
CALL
Immunic
IMUX
$178M
| $229K | ﹤0.01% |
25,970
+12,120
| +88% | +$107K |
|
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.