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 | |
|---|---|---|---|---|---|---|
5901
CALL
SS&C Technologies
SSNC
$18.4B
| $88K | ﹤0.01% |
1,000
-7,500
| -88% | -$649K |
|
5902
PUT
Neuronetics
STIM
$142M
| $88K | ﹤0.01% |
32,400
+16,100
| +99% | +$57.2K |
|
5903
PUT
TFI International
TFII
$11.1B
| $88K | ﹤0.01% |
1,000
-2,600
| -72% | -$238K |
|
|
UHT
5904
Universal Health Realty Income Trust
UHT
$604M
| $88K | ﹤0.01% |
+2,254
| New | +$90.7K |
|
5905
PUT
Vishay Intertechnology
VSH
$5.29B
| $88K | ﹤0.01% |
5,800
-6,400
| -52% | -$101K |
|
5906
WisdomTree Artificial Intelligence and Innovation Fund
WTAI
$590M
| $88K | ﹤0.01% |
+3,105
| New | +$80.8K |
|
5907
CALL
BrightSpring Health Services
BTSG
$11.7B
| $88K | ﹤0.01% |
3,000
-300
| -9% | -$6.97K |
|
|
QQQP
5908
Tradr 2X Long Innovation 100 Quarterly ETF
QQQP
$17.6M
| $88K | ﹤0.01% |
519
+408
| +368% | +$63.8K |
|
5909
PUT
Buckle
BKE
$2.26B
| $87K | ﹤0.01% |
1,500
-1,400
| -48% | -$75.7K |
|
5910
PUT
Cirrus Logic
CRUS
$6.53B
| $87K | ﹤0.01% |
700
+500
| +250% | +$55.7K |
|
5911
iShares MSCI Taiwan ETF
EWT
$9.85B
| $87K | ﹤0.01% |
+1,375
| New | +$82.8K |
|
5912
Flowserve
FLS
$9.66B
| $87K | ﹤0.01% |
1,652
+1,319
| +396% | +$71.6K |
|
5913
Geron
GERN
$783M
| $87K | ﹤0.01% |
63,602
-73,806
| -54% | -$98.3K |
|
5914
PUT
International Seaways
INSW
$4.76B
| $87K | ﹤0.01% |
1,900
-1,100
| -37% | -$47.5K |
|
5915
Janux Therapeutics
JANX
$918M
| $87K | ﹤0.01% |
3,596
-2,652
| -42% | -$64.6K |
|
5916
PUT
PAR Technology
PAR
$699M
| $87K | ﹤0.01% |
2,200
+1,200
| +120% | +$66.3K |
|
5917
PUT
Procore
PCOR
$8.34B
| $87K | ﹤0.01% |
1,200
-600
| -33% | -$41.9K |
|
5918
Perion Network
PERI
$372M
| $87K | ﹤0.01% |
9,113
+6,584
| +260% | +$65.9K |
|
5919
Rimini Street
RMNI
$436M
| $87K | ﹤0.01% |
18,783
+16,134
| +609% | +$71.6K |
|
5920
PUT
Scholastic
SCHL
$767M
| $87K | ﹤0.01% |
3,200
-5,500
| -63% | -$136K |
|
|
UMH
5921
PUT
UMH Properties
UMH
$1.29B
| $87K | ﹤0.01% |
5,900
+1,000
| +20% | +$16K |
|
5922
PUT
United Microelectronic
UMC
$48.1B
| $87K | ﹤0.01% |
11,600
+4,400
| +61% | +$31.2K |
|
5923
VinFast Auto
VFS
$7.25B
| $87K | ﹤0.01% |
27,126
-19,292
| -42% | -$66.2K |
|
5924
PUT
Wyndham Hotels & Resorts
WH
$5.58B
| $87K | ﹤0.01% |
+1,100
| New | +$94.7K |
|
|
SOBO
5925
CALL
South Bow Corp
SOBO
$7.73B
| $87K | ﹤0.01% |
3,100
+2,600
| +520% | +$70.7K |
|
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.