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 | |
|---|---|---|---|---|---|---|
5751
NovoCure
NVCR
$1.73B
| $100K | ﹤0.01% |
+7,815
| New | +$104K |
|
5752
PUT
WPP
WPP
$4.36B
| $100K | ﹤0.01% |
4,000
+1,200
| +43% | +$32.8K |
|
|
LENZ
5753
LENZ Therapeutics
LENZ
$166M
| $100K | ﹤0.01% |
+2,147
| New | +$78.9K |
|
5754
PUT
Archrock
AROC
$6.27B
| $99K | ﹤0.01% |
3,800
+3,500
| +1,167% | +$84.4K |
|
5755
Virtus Biotech Clinical Trials ETF
BBC
$46.3M
| $99K | ﹤0.01% |
+3,661
| New | +$83.5K |
|
5756
ProShares Ultra Bloomberg Natural Gas
BOIL
$344M
| $99K | ﹤0.01% |
1,655
-10,079
| -86% | -$687K |
|
5757
PUT
OSI Systems
OSIS
$3.65B
| $99K | ﹤0.01% |
400
-400
| -50% | -$91.3K |
|
5758
Outfront Media
OUT
$5.61B
| $99K | ﹤0.01% |
+5,433
| New | +$98.6K |
|
5759
CALL
Principal Financial Group
PFG
$24.3B
| $99K | ﹤0.01% |
1,200
-800
| -40% | -$63.9K |
|
5760
Insulet
PODD
$11.5B
| $99K | ﹤0.01% |
+323
| New | +$101K |
|
5761
CALL
Tiziana Life Sciences
TLSA
$131M
| $99K | ﹤0.01% |
45,900
+44,800
| +4,073% | +$82.9K |
|
5762
PUT
Trupanion
TRUP
$1.07B
| $99K | ﹤0.01% |
2,300
-4,900
| -68% | -$233K |
|
5763
CALL
Skye Bioscience
SKYE
$20M
| $99K | ﹤0.01% |
25,300
+23,800
| +1,587% | +$89.9K |
|
|
LAR
5764
Lithium Argentina AG
LAR
$985M
| $99K | ﹤0.01% |
29,762
+25,031
| +529% | +$75.7K |
|
5765
CALL
Invesco CurrencyShares Canadian Dollar Trust
FXC
$73.2M
| $98K | ﹤0.01% |
1,400
-4,800
| -77% | -$341K |
|
5766
LG Display
LPL
$3B
| $98K | ﹤0.01% |
18,775
+18,681
| +19,873% | +$77.6K |
|
5767
Lexicon Pharmaceuticals
LXRX
$1.03B
| $98K | ﹤0.01% |
73,287
+20,607
| +39% | +$23.4K |
|
5768
CALL
Nabors Industries
NBR
$1.27B
| $98K | ﹤0.01% |
2,400
-55,000
| -96% | -$1.96M |
|
5769
CALL
OneSpan
OSPN
$574M
| $98K | ﹤0.01% |
6,200
+1,000
| +19% | +$15.2K |
|
|
PRA
5770
PUT
DELISTED
ProAssurance
PRA
| $98K | ﹤0.01% |
4,100
-1,200
| -23% | -$28.6K |
|
|
SFIX
5771
PUT
Stitch Fix
SFIX
$536M
| $98K | ﹤0.01% |
22,600
-23,700
| -51% | -$117K |
|
5772
CALL
Tanger
SKT
$4.67B
| $98K | ﹤0.01% |
2,900
-2,100
| -42% | -$68.5K |
|
|
SNV
5773
PUT
DELISTED
Synovus
SNV
| $98K | ﹤0.01% |
2,000
+700
| +54% | +$35.9K |
|
|
SPNS
5774
CALL
DELISTED
Sapiens International
SPNS
| $98K | ﹤0.01% |
+2,300
| New | +$83.7K |
|
5775
CALL
Upland Software
UPLD
$12.8M
| $98K | ﹤0.01% |
+4,150
| New | +$94.4K |
|
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.