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 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.59% |
| 2 | Consumer Discretionary | 0.21% |
| 3 | Healthcare | 0.2% |
| 4 | Industrials | 0.18% |
| 5 | Communication Services | 0.16% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
7551
CALL
Digimarc Corp
DMRC
$143M
| $3.94K | ﹤0.01% |
+600
| New | +$5.09K |
|
7552
PUT
Allot
ALLT
$362M
| $3.93K | ﹤0.01% |
400
-22,500
| -98% | -$216K |
|
7553
CALL
Titan International
TWI
$492M
| $3.92K | ﹤0.01% |
500
-48,300
| -99% | -$378K |
|
7554
iShares MSCI All Country Asia ex Japan ETF
AAXJ
$3.51B
| $3.91K | ﹤0.01% |
+42
| New | +$3.9K |
|
7555
CALL
MDU Resources
MDU
$4.18B
| $3.9K | ﹤0.01% |
200
-900
| -82% | -$17.7K |
|
7556
PUT
Fuel Tech
FTEK
$43M
| $3.9K | ﹤0.01% |
2,500
| – | – |
|
7557
IBEX
IBEX
$489M
| $3.89K | ﹤0.01% |
+102
| New | +$3.77K |
|
7558
Scansource
SCSC
$1.17B
| $3.87K | ﹤0.01% |
99
-986
| -91% | -$40.7K |
|
7559
Simmons First National
SFNC
$3.39B
| $3.86K | ﹤0.01% |
+205
| New | +$3.8K |
|
7560
Popular Inc
BPOP
$11B
| $3.86K | ﹤0.01% |
31
-101
| -77% | -$11.9K |
|
7561
PUT
Allogene Therapeutics
ALLO
$625M
| $3.84K | ﹤0.01% |
2,800
-300
| -10% | -$396 |
|
7562
CALL
Fate Therapeutics
FATE
$275M
| $3.83K | ﹤0.01% |
3,900
-16,500
| -81% | -$19.8K |
|
7563
PUT
GH Research
GHRS
$1.92B
| $3.81K | ﹤0.01% |
300
-14,400
| -98% | -$196K |
|
7564
WisdomTree India Earnings Fund ETF
EPI
$2.04B
| $3.79K | ﹤0.01% |
82
-809
| -91% | -$37.1K |
|
|
NNEX
7565
DELISTED
Tradr 2X Long NNE Daily ETF
NNEX
| $3.79K | ﹤0.01% |
+400
| New | +$7.3K |
|
|
BLFY
7566
DELISTED
Blue Foundry Bancorp
BLFY
| $3.79K | ﹤0.01% |
+305
| New | +$3.04K |
|
7567
PUT
LG Display
LPL
$2.79B
| $3.79K | ﹤0.01% |
+900
| New | +$4.2K |
|
7568
PUT
Limoneira
LMNR
$244M
| $3.79K | ﹤0.01% |
300
-1,600
| -84% | -$22.6K |
|
7569
PUT
Foghorn Therapeutics
FHTX
$278M
| $3.78K | ﹤0.01% |
+700
| New | +$3.17K |
|
7570
CALL
American Public Education
APEI
$940M
| $3.78K | ﹤0.01% |
100
| – | – |
|
|
TRVG
7571
CALL
trivago
TRVG
$385M
| $3.77K | ﹤0.01% |
1,300
-1,000
| -43% | -$3.04K |
|
7572
Townsquare Media
TSQ
$105M
| $3.76K | ﹤0.01% |
+731
| New | +$4.11K |
|
7573
PUT
NRC Health Common Stock
NRC
$412M
| $3.75K | ﹤0.01% |
200
+100
| +100% | +$1.51K |
|
|
LTCC
7574
CALL
Canary Litecoin ETF
LTCC
$5.15M
| $3.75K | ﹤0.01% |
+200
| New | +$4.22K |
|
7575
CALL
Phibro Animal Health
PAHC
$1.5B
| $3.74K | ﹤0.01% |
100
-100
| -50% | -$4.06K |
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading withdrew a net $23.2B in Q4 2025, closing 2,184 positions and reducing 4,088 holdings. Its most notable exit was iShares Russell 2000 ETF, an estimated $149M position sold in full.
By sector, the portfolio is most concentrated in Technology at 0.59% of assets, down from 0.79% a quarter earlier, followed by Consumer Discretionary and Healthcare.
Against the trend, Simplex Trading opened a new position in Western Digital worth $58.9M.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.