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 | |
|---|---|---|---|---|---|---|
3076
PUT
Keros Therapeutics
KROS
$202M
| $972K | ﹤0.01% |
61,500
-83,500
| -58% | -$1.23M |
|
3077
PUT
Ormat Technologies
ORA
$6.28B
| $972K | ﹤0.01% |
10,100
-4,700
| -32% | -$424K |
|
3078
CALL
Amylyx Pharmaceuticals
AMLX
$2.17B
| $971K | ﹤0.01% |
71,500
+46,500
| +186% | +$438K |
|
|
THS
3079
DELISTED
Treehouse Foods
THS
| $971K | ﹤0.01% |
+48,049
| New | +$911K |
|
3080
CALL
Kyndryl
KD
$2.81B
| $969K | ﹤0.01% |
32,300
-92,000
| -74% | -$3.16M |
|
3081
CALL
iShares Convertible Bond ETF
ICVT
$7.21B
| $968K | ﹤0.01% |
28,800
-26,100
| -48% | -$2.45M |
|
3082
CALL
Trevi Therapeutics
TRVI
$2.57B
| $967K | ﹤0.01% |
105,700
-34,900
| -25% | -$262K |
|
3083
CALL
Xcel Energy
XEL
$50.4B
| $967K | ﹤0.01% |
12,000
-15,100
| -56% | -$1.09M |
|
3084
PUT
Coursera
COUR
$1.61B
| $966K | ﹤0.01% |
82,500
-5,000
| -6% | -$54.3K |
|
3085
Burford Capital
BUR
$922M
| $965K | ﹤0.01% |
80,745
-33,062
| -29% | -$442K |
|
|
PPTA
3086
Perpetua Resources
PPTA
$2.28B
| $965K | ﹤0.01% |
+47,717
| New | +$806K |
|
3087
CALL
Sony
SONY
$131B
| $963K | ﹤0.01% |
366,100
+197,300
| +117% | +$5.31M |
|
3088
Wingstop
WING
$3.74B
| $963K | ﹤0.01% |
3,828
-494
| -11% | -$153K |
|
3089
PUT
Boot Barn
BOOT
$4.71B
| $961K | ﹤0.01% |
5,800
+1,700
| +41% | +$293K |
|
3090
Cogent Biosciences
COGT
$6.91B
| $961K | ﹤0.01% |
66,988
-12,373
| -16% | -$147K |
|
|
DX
3091
PUT
Dynex Capital
DX
$3B
| $961K | ﹤0.01% |
78,200
+55,300
| +241% | +$692K |
|
|
SOHU
3092
CALL
Sohu.com
SOHU
$345M
| $961K | ﹤0.01% |
61,500
+61,400
| +61,400% | +$938K |
|
3093
CALL
Cemex
CX
$17.6B
| $960K | ﹤0.01% |
106,800
+104,600
| +4,755% | +$893K |
|
3094
CALL
Genesis Energy
GEL
$1.81B
| $960K | ﹤0.01% |
57,500
-48,200
| -46% | -$810K |
|
3095
CALL
Lionsgate Studios
LION
$3.86B
| $958K | ﹤0.01% |
140,800
+135,800
| +2,716% | +$874K |
|
3096
CALL
Willdan Group
WLDN
$1.09B
| $957K | ﹤0.01% |
+9,900
| New | +$937K |
|
3097
Red Cat Holdings
RCAT
$1.19B
| $956K | ﹤0.01% |
+92,398
| New | +$863K |
|
3098
CALL
Millicom
TIGO
$16B
| $956K | ﹤0.01% |
19,700
+18,400
| +1,415% | +$807K |
|
|
OTLY
3099
CALL
Oatly Group
OTLY
$447M
| $955K | ﹤0.01% |
59,000
-22,900
| -28% | -$369K |
|
3100
BRC Group Holdings
RILY
$273M
| $955K | ﹤0.01% |
159,836
+81,549
| +104% | +$451K |
|
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.