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 | |
|---|---|---|---|---|---|---|
|
DDL
2976
CALL
Dingdong
DDL
$523M
| $696K | ﹤0.01% |
279,700
+70,300
| +34% | +$140K |
|
2977
DraftKings
DKNG
$12B
| $696K | ﹤0.01% |
20,210
-102,897
| -84% | -$3.38M |
|
2978
CALL
SouthState Bank Corp
SSB
$10.2B
| $696K | ﹤0.01% |
7,400
-2,500
| -25% | -$232K |
|
2979
CALL
Dyne Therapeutics
DYN
$4.24B
| $696K | ﹤0.01% |
35,600
+29,800
| +514% | +$564K |
|
2980
CALL
CoreCivic
CXW
$3.09B
| $696K | ﹤0.01% |
36,400
+500
| +1% | +$9.16K |
|
2981
PUT
Amkor Technology
AMKR
$15B
| $695K | ﹤0.01% |
17,600
-62,900
| -78% | -$2.24M |
|
2982
CALL
WillScot Mobile Mini Holdings
WSC
$4.85B
| $695K | ﹤0.01% |
36,900
-14,900
| -29% | -$300K |
|
|
SAFE
2983
CALL
Safehold
SAFE
$1.19B
| $694K | ﹤0.01% |
50,700
+11,700
| +30% | +$166K |
|
2984
CALL
FT Vest Gold Strategy Target Income ETF
IGLD
$511M
| $693K | ﹤0.01% |
14,900
+11,700
| +366% | +$292K |
|
2985
BBVA Argentina
BBAR
$3.92B
| $692K | ﹤0.01% |
38,322
+24,275
| +173% | +$348K |
|
2986
PUT
Brookfield Infrastructure Partners
BIP
$18.6B
| $691K | ﹤0.01% |
19,900
-1,200
| -6% | -$41.8K |
|
|
BRR
2987
PUT
ProCap Financial Inc
BRR
$167M
| $690K | ﹤0.01% |
195,400
-105,100
| -35% | -$838K |
|
2988
PUT
Lionsgate Studios
LION
$3.86B
| $688K | ﹤0.01% |
75,400
+46,600
| +162% | +$332K |
|
2989
PUT
Green Plains
GPRE
$1.15B
| $687K | ﹤0.01% |
70,100
+25,200
| +56% | +$254K |
|
|
HIMX
2990
PUT
Himax Technologies
HIMX
$2.22B
| $686K | ﹤0.01% |
83,700
-18,200
| -18% | -$154K |
|
2991
Manchester United
MANU
$3.96B
| $685K | ﹤0.01% |
43,015
+16,170
| +60% | +$261K |
|
2992
Consolidated Edison
ED
$41.1B
| $684K | ﹤0.01% |
6,884
+2,735
| +66% | +$271K |
|
2993
Herc Holdings
HRI
$5.34B
| $683K | ﹤0.01% |
+4,605
| New | +$631K |
|
2994
CALL
Arbe Robotics
ARBE
$83.6M
| $683K | ﹤0.01% |
578,900
+327,100
| +130% | +$540K |
|
|
APLS
2995
DELISTED
Apellis Pharmaceuticals
APLS
| $683K | ﹤0.01% |
27,187
-26,714
| -50% | -$627K |
|
2996
PUT
Energy Vault
NRGV
$531M
| $682K | ﹤0.01% |
147,900
-85,000
| -36% | -$325K |
|
2997
PUT
Banco Santander
SAN
$200B
| $682K | ﹤0.01% |
58,100
-83,600
| -59% | -$887K |
|
2998
Critical Metals Corp
CRML
$887M
| $680K | ﹤0.01% |
97,916
-20,438
| -17% | -$223K |
|
2999
CALL
Republic Services
RSG
$66.7B
| $678K | ﹤0.01% |
3,200
-4,000
| -56% | -$861K |
|
3000
CALL
Lifestance Health
LFST
$4.15B
| $678K | ﹤0.01% |
96,300
+89,500
| +1,316% | +$540K |
|
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.