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 | |
|---|---|---|---|---|---|---|
5251
PUT
SkyWater Technology
SKYT
$1.6B
| $154K | ﹤0.01% |
8,300
+7,000
| +538% | +$80.9K |
|
|
LB
5252
CALL
LandBridge Co
LB
$2.16B
| $154K | ﹤0.01% |
2,900
-4,700
| -62% | -$259K |
|
5253
CALL
Bain Capital Specialty
BCSF
$806M
| $153K | ﹤0.01% |
10,800
-7,100
| -40% | -$108K |
|
5254
PUT
Ceco Environmental
CECO
$3.85B
| $153K | ﹤0.01% |
3,000
+2,400
| +400% | +$102K |
|
5255
Genworth Financial
GNW
$3.76B
| $153K | ﹤0.01% |
+17,201
| New | +$142K |
|
5256
PUT
Saratoga Investment
SAR
$312M
| $153K | ﹤0.01% |
6,300
+2,900
| +85% | +$72.4K |
|
5257
CALL
SI-BONE Inc
SIBN
$788M
| $153K | ﹤0.01% |
10,400
-16,000
| -61% | -$261K |
|
5258
CALL
Marriott Vacations Worldwide
VAC
$3.35B
| $153K | ﹤0.01% |
2,300
-2,300
| -50% | -$177K |
|
5259
CALL
Kyverna Therapeutics
KYTX
$444M
| $153K | ﹤0.01% |
25,600
-6,000
| -19% | -$24K |
|
5260
Aldeyra Therapeutics
ALDX
$92.9M
| $152K | ﹤0.01% |
29,176
+7,993
| +38% | +$41.7K |
|
5261
PUT
AMN Healthcare
AMN
$1.3B
| $152K | ﹤0.01% |
7,900
-3,600
| -31% | -$70.3K |
|
5262
PUT
Costamare
CMRE
$1.88B
| $152K | ﹤0.01% |
12,800
+12,600
| +6,300% | +$138K |
|
|
LAND
5263
CALL
Gladstone Land Corp
LAND
$350M
| $152K | ﹤0.01% |
16,600
-400
| -2% | -$3.78K |
|
5264
PUT
RenaissanceRe
RNR
$13.3B
| $152K | ﹤0.01% |
+600
| New | +$145K |
|
|
ASRT
5265
CALL
DELISTED
Assertio
ASRT
| $151K | ﹤0.01% |
11,433
-1,640
| -13% | -$19.1K |
|
5266
PUT
Fidelity National Financial
FNF
$13.9B
| $151K | ﹤0.01% |
2,500
+200
| +9% | +$11.6K |
|
5267
PUT
IDT Corp
IDT
$1.64B
| $151K | ﹤0.01% |
+2,900
| New | +$181K |
|
|
LNW
5268
CALL
DELISTED
Light & Wonder
LNW
| $151K | ﹤0.01% |
1,800
-1,700
| -49% | -$156K |
|
5269
CALL
Unisys
UIS
$209M
| $151K | ﹤0.01% |
38,900
+10,800
| +38% | +$43.8K |
|
5270
CALL
Upbound Group
UPBD
$1.13B
| $151K | ﹤0.01% |
6,400
-8,600
| -57% | -$212K |
|
|
AMRZ
5271
Amrize Ltd
AMRZ
$27.1B
| $151K | ﹤0.01% |
+3,113
| New | +$159K |
|
5272
Moog Inc Class A
MOG.A
$12.4B
| $150K | ﹤0.01% |
+724
| New | +$140K |
|
5273
CALL
NB Bancorp
NBBK
$1.01B
| $150K | ﹤0.01% |
+8,500
| New | +$156K |
|
5274
PUT
Lionsgate Studios
LION
$3.95B
| $150K | ﹤0.01% |
28,800
+19,300
| +203% | +$124K |
|
|
CRCG
5275
PUT
Leverage Shares 2X Long CRCL Daily ETF
CRCG
$82M
| $150K | ﹤0.01% |
+1,410
| New | +$139K |
|
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.