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 | |
|---|---|---|---|---|---|---|
3451
CALL
California Resources
CRC
$4.42B
| $429K | ﹤0.01% |
9,600
+7,500
| +357% | +$356K |
|
3452
CALL
Annovis Bio
ANVS
$71M
| $429K | ﹤0.01% |
124,000
+77,800
| +168% | +$234K |
|
3453
PUT
Build-A-Bear
BBW
$450M
| $429K | ﹤0.01% |
7,000
-2,300
| -25% | -$125K |
|
|
HUYA
3454
CALL
Huya Inc
HUYA
$561M
| $428K | ﹤0.01% |
148,500
-24,300
| -14% | -$71.2K |
|
3455
CALL
Kadant
KAI
$3.73B
| $428K | ﹤0.01% |
+1,500
| New | +$426K |
|
|
NVMI
3456
PUT
Nova
NVMI
$12.9B
| $427K | ﹤0.01% |
1,300
-3,800
| -75% | -$1.22M |
|
3457
PUT
Amdocs
DOX
$5.85B
| $427K | ﹤0.01% |
5,300
+800
| +18% | +$64.3K |
|
3458
CALL
Nano X Imaging
NNOX
$61.1M
| $426K | ﹤0.01% |
152,300
+9,900
| +7% | +$35.6K |
|
3459
PUT
Upexi
UPXI
$62.8M
| $426K | ﹤0.01% |
253,700
-702,500
| -73% | -$2.65M |
|
3460
Full Truck Alliance
YMM
$9.67B
| $426K | ﹤0.01% |
39,695
-66,155
| -62% | -$793K |
|
3461
PagerDuty
PD
$800M
| $426K | ﹤0.01% |
32,472
+4,163
| +15% | +$60.7K |
|
|
ONC
3462
CALL
BeOne Medicines Ltd
ONC
$34B
| $425K | ﹤0.01% |
1,400
-1,000
| -42% | -$327K |
|
3463
GXO Logistics
GXO
$6.13B
| $425K | ﹤0.01% |
8,079
-19,598
| -71% | -$1.03M |
|
3464
CALL
Village Farms International
VFF
$246M
| $424K | ﹤0.01% |
116,300
-153,400
| -57% | -$534K |
|
3465
CALL
Outfront Media
OUT
$5.69B
| $424K | ﹤0.01% |
17,600
+17,100
| +3,420% | +$356K |
|
3466
Vanguard Total International Stock ETF
VXUS
$153B
| $423K | ﹤0.01% |
5,608
+2,954
| +111% | +$221K |
|
3467
Talkspace
TALK
$874M
| $423K | ﹤0.01% |
116,545
+96,386
| +478% | +$306K |
|
3468
PUT
Nektar Therapeutics
NKTR
$2.37B
| $423K | ﹤0.01% |
10,000
-90,600
| -90% | -$5.07M |
|
3469
PUT
Geron
GERN
$937M
| $423K | ﹤0.01% |
320,100
+309,300
| +2,864% | +$388K |
|
3470
Schneider National
SNDR
$6.4B
| $422K | ﹤0.01% |
15,923
+11,300
| +244% | +$267K |
|
|
DRD
3471
DRDGold
DRD
$1.79B
| $422K | ﹤0.01% |
13,616
+7,278
| +115% | +$208K |
|
3472
CALL
Insperity
NSP
$1.98B
| $422K | ﹤0.01% |
10,900
-6,600
| -38% | -$264K |
|
3473
PUT
CenterPoint Energy
CNP
$29B
| $422K | ﹤0.01% |
11,000
-27,100
| -71% | -$1.06M |
|
3474
CALL
CytomX Therapeutics
CTMX
$694M
| $422K | ﹤0.01% |
99,000
-232,900
| -70% | -$885K |
|
3475
CALL
Aldeyra Therapeutics
ALDX
$94.1M
| $422K | ﹤0.01% |
81,400
+57,400
| +239% | +$295K |
|
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.