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 | |
|---|---|---|---|---|---|---|
3151
Fabrinet
FN
$16.9B
| $913K | ﹤0.01% |
2,504
+2,148
| +603% | +$707K |
|
3152
PUT
Genius Sports
GENI
$1.94B
| $913K | ﹤0.01% |
73,800
+19,800
| +37% | +$237K |
|
3153
PUT
Illinois Tool Works
ITW
$81.9B
| $912K | ﹤0.01% |
3,500
+1,100
| +46% | +$287K |
|
3154
Delta Air Lines
DAL
$57B
| $911K | ﹤0.01% |
16,062
-173,955
| -92% | -$9.93M |
|
3155
CALL
Beam Therapeutics
BEAM
$2.58B
| $907K | ﹤0.01% |
37,400
+15,400
| +70% | +$306K |
|
3156
PUT
Cogent Biosciences
COGT
$6.91B
| $907K | ﹤0.01% |
63,200
+17,300
| +38% | +$205K |
|
|
HTT
3157
High Templar Tech Ltd
HTT
$376M
| $907K | ﹤0.01% |
212,597
+192,132
| +939% | +$771K |
|
3158
PUT
Velocity Financial
VEL
$692M
| $907K | ﹤0.01% |
50,000
-36,100
| -42% | -$659K |
|
3159
Middleby
MIDD
$6.15B
| $906K | ﹤0.01% |
6,821
-3,631
| -35% | -$504K |
|
3160
CALL
AtaiBeckley Inc
ATAI
$2.65B
| $902K | ﹤0.01% |
170,600
+132,700
| +350% | +$539K |
|
|
DX
3161
Dynex Capital
DX
$3B
| $902K | ﹤0.01% |
73,474
+53,663
| +271% | +$672K |
|
3162
CALL
Flywire
FLYW
$1.99B
| $901K | ﹤0.01% |
66,600
+59,900
| +894% | +$737K |
|
3163
PUT
Palladyne AI
PDYN
$244M
| $901K | ﹤0.01% |
105,000
+77,600
| +283% | +$644K |
|
|
HIMX
3164
PUT
Himax Technologies
HIMX
$2.22B
| $899K | ﹤0.01% |
101,900
+32,500
| +47% | +$279K |
|
3165
CALL
Ezcorp Inc
EZPW
$1.87B
| $898K | ﹤0.01% |
47,200
+41,000
| +661% | +$642K |
|
3166
CALL
Incyte
INCY
$23.7B
| $898K | ﹤0.01% |
10,600
-12,900
| -55% | -$1.02M |
|
3167
State Street SPDR Portfolio Long Term Treasury ETF
SPTL
$10.6B
| $898K | ﹤0.01% |
+33,353
| New | +$881K |
|
3168
CALL
HF Sinclair
DINO
$16.4B
| $895K | ﹤0.01% |
17,100
-96,800
| -85% | -$4.59M |
|
3169
PUT
Kyndryl
KD
$2.81B
| $894K | ﹤0.01% |
29,800
-12,700
| -30% | -$436K |
|
3170
PUT
State Street SPDR S&P MIDCAP 400 ETF Trust
MDY
$26.9B
| $894K | ﹤0.01% |
1,500
-2,600
| -63% | -$1.53M |
|
3171
BlackBerry
BB
$4.93B
| $892K | ﹤0.01% |
182,911
+163,770
| +856% | +$649K |
|
3172
CALL
Graphic Packaging
GPK
$3.3B
| $892K | ﹤0.01% |
45,600
+39,000
| +591% | +$848K |
|
3173
Patterson-UTI
PTEN
$3.57B
| $892K | ﹤0.01% |
172,327
+51,269
| +42% | +$295K |
|
3174
Global X Robotics & Artificial Intelligence ETF
BOTZ
$3.2B
| $889K | ﹤0.01% |
25,119
+20,760
| +476% | +$700K |
|
3175
Cameco
CCJ
$38.9B
| $889K | ﹤0.01% |
+10,602
| New | +$822K |
|
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.