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 | |
|---|---|---|---|---|---|---|
4476
PUT
SouthState Bank Corp
SSB
$10.3B
| $296K | ﹤0.01% |
3,000
+1,500
| +100% | +$147K |
|
|
AIFC
4477
AI Financial Corp
AIFC
$51.7M
| $296K | ﹤0.01% |
110,382
+86,845
| +369% | +$520K |
|
|
SMU
4478
CALL
Tradr 2X Long SMR Daily ETF
SMU
$38.9M
| $296K | ﹤0.01% |
+953
| New | +$412K |
|
4479
CALL
Absci
ABSI
$1.17B
| $295K | ﹤0.01% |
97,300
-68,100
| -41% | -$188K |
|
4480
CALL
American Resources Corp
AREC
$183M
| $295K | ﹤0.01% |
109,600
+101,300
| +1,220% | +$173K |
|
4481
Immersion
IMMR
$243M
| $295K | ﹤0.01% |
40,315
-5,566
| -12% | -$40.4K |
|
|
RWT
4482
CALL
Redwood Trust
RWT
$588M
| $295K | ﹤0.01% |
51,100
+35,100
| +219% | +$210K |
|
|
NTSK
4483
CALL
Netskope Inc
NTSK
$4.83B
| $295K | ﹤0.01% |
+13,000
| New | +$309K |
|
4484
CALL
Beazer Homes USA
BZH
$888M
| $294K | ﹤0.01% |
12,000
-121,200
| -91% | -$2.98M |
|
|
PINE
4485
CALL
Alpine Income Property Trust
PINE
$336M
| $294K | ﹤0.01% |
20,800
+20,000
| +2,500% | +$292K |
|
4486
CALL
Replimune Group
REPL
$454M
| $294K | ﹤0.01% |
70,300
-143,500
| -67% | -$917K |
|
4487
CALL
SES AI
SES
$187M
| $294K | ﹤0.01% |
176,400
+108,000
| +158% | +$129K |
|
|
TRON
4488
CALL
Tron Inc
TRON
$693M
| $294K | ﹤0.01% |
152,800
+151,200
| +9,450% | +$895K |
|
|
ATYR
4489
CALL
aTyr Pharma
ATYR
$47.4M
| $294K | ﹤0.01% |
407,800
+157,800
| +63% | +$715K |
|
|
BNCWW
4490
PUT
CEA Industries Inc Warrant
BNCWW
$51.9K
| $293K | ﹤0.01% |
+37,600
| New | +$5.66K |
|
4491
PUT
DT Midstream
DTM
$13.9B
| $293K | ﹤0.01% |
2,600
+2,300
| +767% | +$240K |
|
4492
CALL
Flowers Foods
FLO
$1.58B
| $293K | ﹤0.01% |
22,500
+19,700
| +704% | +$299K |
|
4493
Icahn Enterprises
IEP
$5.1B
| $293K | ﹤0.01% |
34,864
-26,960
| -44% | -$236K |
|
|
LB
4494
PUT
LandBridge Co
LB
$2.09B
| $293K | ﹤0.01% |
5,500
+1,600
| +41% | +$88.2K |
|
4495
CALL
Geron
GERN
$898M
| $292K | ﹤0.01% |
213,300
+117,800
| +123% | +$157K |
|
4496
PUT
Hamilton Insurance Group
HG
$3.63B
| $292K | ﹤0.01% |
11,800
+8,500
| +258% | +$194K |
|
4497
CALL
LSB Industries
LXU
$824M
| $292K | ﹤0.01% |
37,100
-6,200
| -14% | -$50.3K |
|
4498
PUT
C.H. Robinson
CHRW
$20.5B
| $291K | ﹤0.01% |
2,200
-3,500
| -61% | -$411K |
|
4499
CALL
Monte Rosa Therapeutics
GLUE
$1.82B
| $291K | ﹤0.01% |
39,300
+6,300
| +19% | +$33.4K |
|
4500
Ligand Pharmaceuticals
LGND
$5.77B
| $291K | ﹤0.01% |
1,647
+1,107
| +205% | +$165K |
|
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.