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 | |
|---|---|---|---|---|---|---|
2401
American Tower
AMT
$77.7B
| $1.86M | ﹤0.01% |
+9,688
| New | +$2.02M |
|
2402
CALL
LPL Financial
LPLA
$26.3B
| $1.86M | ﹤0.01% |
5,600
+2,400
| +75% | +$870K |
|
2403
PUT
Altimmune
ALT
$539M
| $1.86M | ﹤0.01% |
494,100
+152,300
| +45% | +$588K |
|
2404
CALL
Qfin Holdings
QFIN
$1.61B
| $1.85M | ﹤0.01% |
64,300
+23,200
| +56% | +$789K |
|
2405
PUT
Flex
FLEX
$43.4B
| $1.85M | ﹤0.01% |
32,300
+13,500
| +72% | +$717K |
|
2406
CALL
Howard Hughes
HHH
$3.93B
| $1.85M | ﹤0.01% |
22,500
+11,100
| +97% | +$822K |
|
|
QXO
2407
QXO Inc
QXO
$14.2B
| $1.85M | ﹤0.01% |
97,001
-105,887
| -52% | -$2.19M |
|
2408
PUT
Middleby
MIDD
$6.05B
| $1.85M | ﹤0.01% |
13,900
+13,500
| +3,375% | +$1.87M |
|
2409
CALL
Asana
ASAN
$1.58B
| $1.85M | ﹤0.01% |
138,200
-2,800
| -2% | -$39.6K |
|
2410
Axcelis
ACLS
$4.12B
| $1.84M | ﹤0.01% |
18,887
+4,565
| +32% | +$368K |
|
2411
CALL
Procore
PCOR
$6.46B
| $1.84M | ﹤0.01% |
25,300
-8,300
| -25% | -$580K |
|
2412
PUT
Rayonier Advanced Materials
RYAM
$565M
| $1.84M | ﹤0.01% |
255,000
+97,400
| +62% | +$502K |
|
2413
iShares 3-7 Year Treasury Bond ETF
IEI
$18.1B
| $1.84M | ﹤0.01% |
15,403
-14,739
| -49% | -$1.75M |
|
2414
PUT
Freshpet
FRPT
$2.83B
| $1.83M | ﹤0.01% |
33,300
+6,300
| +23% | +$390K |
|
2415
PUT
Zions Bancorporation
ZION
$10.1B
| $1.83M | ﹤0.01% |
32,400
+3,600
| +13% | +$200K |
|
|
UCD
2416
PUT
DELISTED
PROSHARES ULTRA BLOOMBERG COMMODITY
UCD
| $1.83M | ﹤0.01% |
35,100
-30,800
| -47% | -$1.61M |
|
2417
PUT
Similarweb
SMWB
$551M
| $1.83M | ﹤0.01% |
197,000
+57,300
| +41% | +$513K |
|
2418
CALL
Paycom
PAYC
$6.78B
| $1.83M | ﹤0.01% |
8,800
-2,400
| -21% | -$541K |
|
2419
PUT
International Flavors & Fragrances
IFF
$19.4B
| $1.83M | ﹤0.01% |
29,700
+25,200
| +560% | +$1.73M |
|
2420
CALL
Maximus
MMS
$3.14B
| $1.83M | ﹤0.01% |
20,000
+19,700
| +6,567% | +$1.6M |
|
2421
PUT
Sigma Lithium
SGML
$1.08B
| $1.82M | ﹤0.01% |
284,800
-39,200
| -12% | -$236K |
|
2422
CALL
Owens Corning
OC
$11.5B
| $1.82M | ﹤0.01% |
12,900
-12,200
| -49% | -$1.79M |
|
2423
CALL
Fabrinet
FN
$17.1B
| $1.82M | ﹤0.01% |
5,000
+2,100
| +72% | +$691K |
|
|
GENVR
2424
CALL
Gen Digital Inc Contingent Value Rights
GENVR
| $1.82M | ﹤0.01% |
64,200
-10,900
| -15% | -$98.3K |
|
2425
CALL
First Horizon
FHN
$12.1B
| $1.82M | ﹤0.01% |
80,500
+8,000
| +11% | +$178K |
|
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.