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 | |
|---|---|---|---|---|---|---|
3826
CALL
Banco de Chile
BCH
$20.4B
| $296K | ﹤0.01% |
7,800
+7,300
| +1,460% | +$259K |
|
3827
CALL
PetMed Express
PETS
$42.7M
| $296K | ﹤0.01% |
+92,600
| New | +$232K |
|
|
MNTN
3828
CALL
MNTN Inc
MNTN
$702M
| $296K | ﹤0.01% |
24,800
+7,600
| +44% | +$109K |
|
|
SLDE
3829
PUT
Slide Insurance Holdings
SLDE
$2.57B
| $296K | ﹤0.01% |
15,200
+5,900
| +63% | +$98.4K |
|
3830
Valley National Bancorp
VLY
$7.94B
| $296K | ﹤0.01% |
25,326
-142,971
| -85% | -$1.59M |
|
3831
CALL
Dorman Products
DORM
$4.3B
| $296K | ﹤0.01% |
2,400
+100
| +4% | +$13.5K |
|
3832
PUT
Vaxcyte
PCVX
$7.73B
| $295K | ﹤0.01% |
6,400
+4,800
| +300% | +$215K |
|
|
SNV
3833
CALL
DELISTED
Synovus
SNV
| $295K | ﹤0.01% |
5,900
-47,700
| -89% | -$2.29M |
|
3834
CALL
Hallador Energy
HNRG
$668M
| $295K | ﹤0.01% |
15,500
-13,300
| -46% | -$270K |
|
|
BKV
3835
BKV Corp
BKV
$2.61B
| $294K | ﹤0.01% |
10,846
+10,829
| +63,700% | +$272K |
|
3836
PUT
Radiant Logistics
RLGT
$406M
| $294K | ﹤0.01% |
46,500
-7,600
| -14% | -$47.1K |
|
3837
Pebblebrook Hotel Trust
PEB
$2.21B
| $294K | ﹤0.01% |
26,002
-14,540
| -36% | -$160K |
|
|
CAI
3838
PUT
Caris Life Sciences
CAI
$4.4B
| $294K | ﹤0.01% |
10,900
+10,000
| +1,111% | +$282K |
|
3839
Direxion Daily Financial Bear 3x ETF
FAZ
$84.3M
| $294K | ﹤0.01% |
7,643
-8,564
| -53% | -$360K |
|
|
CNR
3840
Core Natural Resources Inc
CNR
$3.92B
| $294K | ﹤0.01% |
+3,318
| New | +$283K |
|
3841
Alcon
ALC
$34B
| $292K | ﹤0.01% |
+3,710
| New | +$286K |
|
3842
T-Mobile US
TMUS
$195B
| $292K | ﹤0.01% |
+1,438
| New | +$305K |
|
3843
NNN REIT
NNN
$9.38B
| $292K | ﹤0.01% |
+7,366
| New | +$302K |
|
3844
PUT
Honda
HMC
$40.2B
| $292K | ﹤0.01% |
9,900
-5,400
| -35% | -$164K |
|
3845
PUT
Brink's
BCO
$4.91B
| $292K | ﹤0.01% |
2,500
+2,400
| +2,400% | +$275K |
|
3846
Kura Oncology
KURA
$805M
| $292K | ﹤0.01% |
28,063
-118,108
| -81% | -$1.24M |
|
3847
CALL
Lennox International
LII
$15.2B
| $291K | ﹤0.01% |
600
-600
| -50% | -$301K |
|
3848
Cooper Companies
COO
$14.2B
| $291K | ﹤0.01% |
3,552
-4,123
| -54% | -$309K |
|
3849
Taboola.com
TBLA
$1.4B
| $291K | ﹤0.01% |
63,138
+46,031
| +269% | +$173K |
|
3850
PUT
Beam Therapeutics
BEAM
$2.67B
| $291K | ﹤0.01% |
10,500
-15,400
| -59% | -$393K |
|
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.