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 | |
|---|---|---|---|---|---|---|
3701
CALL
New Fortress Energy
NFE
$94.3M
| $339K | ﹤0.01% |
297,300
-147,800
| -33% | -$218K |
|
3702
CALL
ACV Auctions
ACVA
$1.43B
| $338K | ﹤0.01% |
42,200
-8,700
| -17% | -$70.4K |
|
3703
CALL
Goldman Sachs Innovate Equity ETF
GINN
$203M
| $338K | ﹤0.01% |
6,400
+4,900
| +327% | +$364K |
|
3704
Wabtec
WAB
$51.7B
| $337K | ﹤0.01% |
1,580
-1,494
| -49% | -$307K |
|
|
FMDG
3705
CALL
DELISTED
Fieldstone Merlin Dynamic Large Cap Growth ETF
FMDG
| $337K | ﹤0.01% |
8,000
+4,700
| +142% | +$198K |
|
3706
PUT
GXO Logistics
GXO
$6.13B
| $337K | ﹤0.01% |
6,400
-17,900
| -74% | -$941K |
|
3707
PUT
Columbia Sportswear
COLM
$3.3B
| $336K | ﹤0.01% |
6,100
-3,800
| -38% | -$203K |
|
3708
PUT
Andersons Inc
ANDE
$2.49B
| $335K | ﹤0.01% |
6,300
+3,600
| +133% | +$176K |
|
3709
PUT
Host Hotels & Resorts
HST
$17.4B
| $333K | ﹤0.01% |
18,800
-92,400
| -83% | -$1.59M |
|
3710
CALL
Bausch + Lomb
BLCO
$5.92B
| $333K | ﹤0.01% |
19,500
+900
| +5% | +$14.3K |
|
|
AIV
3711
CALL
Aimco
AIV
$375M
| $332K | ﹤0.01% |
55,900
+31,100
| +125% | +$186K |
|
3712
CALL
Candel Therapeutics
CADL
$709M
| $332K | ﹤0.01% |
58,700
-26,100
| -31% | -$140K |
|
3713
CALL
Flywire
FLYW
$2.04B
| $331K | ﹤0.01% |
23,400
-43,200
| -65% | -$591K |
|
3714
CALL
Opko Health
OPK
$1.25B
| $331K | ﹤0.01% |
262,900
-6,100
| -2% | -$8.49K |
|
3715
CALL
Fidelity Enhanced Large Cap Core ETF
FELC
$7.9B
| $331K | ﹤0.01% |
5,800
-2,300
| -28% | -$86.7K |
|
3716
CALL
W&T Offshore
WTI
$473M
| $331K | ﹤0.01% |
203,100
+50,400
| +33% | +$96.8K |
|
3717
PUT
Curtiss-Wright
CW
$26.9B
| $331K | ﹤0.01% |
+600
| New | +$335K |
|
3718
CALL
MediWound
MDWD
$188M
| $330K | ﹤0.01% |
17,900
+17,400
| +3,480% | +$318K |
|
3719
CALL
Ollie's Bargain Outlet
OLLI
$4.17B
| $329K | ﹤0.01% |
3,000
-1,500
| -33% | -$181K |
|
3720
CALL
Avalo Therapeutics
AVTX
$1.03B
| $329K | ﹤0.01% |
18,100
+12,700
| +235% | +$214K |
|
|
WCC
3721
WESCO International
WCC
$16.1B
| $328K | ﹤0.01% |
+1,341
| New | +$329K |
|
3722
CALL
Kulicke & Soffa
KLIC
$4.76B
| $328K | ﹤0.01% |
7,200
-700
| -9% | -$29.6K |
|
3723
ANI Pharmaceuticals
ANIP
$1.84B
| $328K | ﹤0.01% |
4,152
+3,540
| +578% | +$307K |
|
3724
OppFi
OPFI
$824M
| $327K | ﹤0.01% |
+31,260
| New | +$317K |
|
3725
CALL
Immunocore
IMCR
$1.7B
| $326K | ﹤0.01% |
9,400
+8,900
| +1,780% | +$314K |
|
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.