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 | |
|---|---|---|---|---|---|---|
2551
Aurora
AUR
$11.7B
| $1.09M | ﹤0.01% |
283,055
-91,261
| -24% | -$418K |
|
2552
PUT
Hycroft Mining Holding Corp
HYMC
$1.85B
| $1.09M | ﹤0.01% |
45,700
+20,800
| +84% | +$230K |
|
2553
Fiverr
FVRR
$376M
| $1.09M | ﹤0.01% |
54,955
+27,168
| +98% | +$585K |
|
2554
CALL
Medifast
MED
$108M
| $1.08M | ﹤0.01% |
101,500
+28,600
| +39% | +$342K |
|
2555
CALL
Spyre Therapeutics
SYRE
$8.87B
| $1.08M | ﹤0.01% |
33,000
+22,700
| +220% | +$593K |
|
2556
PUT
Bitwise Bitcoin ETF
BITB
$2.46B
| $1.08M | ﹤0.01% |
22,700
-33,300
| -59% | -$1.81M |
|
2557
CALL
Helen of Troy
HELE
$663M
| $1.08M | ﹤0.01% |
50,800
+37,000
| +268% | +$755K |
|
2558
PUT
H.B. Fuller
FUL
$3B
| $1.08M | ﹤0.01% |
18,100
-800
| -4% | -$47K |
|
2559
PUT
Markel Group
MKL
$25B
| $1.07M | ﹤0.01% |
500
-100
| -17% | -$203K |
|
|
KLAR
2560
CALL
Klarna Group
KLAR
$6.56B
| $1.07M | ﹤0.01% |
37,100
+27,600
| +291% | +$948K |
|
2561
PUT
Dynatrace
DT
$12.1B
| $1.07M | ﹤0.01% |
24,700
-77,100
| -76% | -$3.59M |
|
2562
CALL
Rollins
ROL
$18.6B
| $1.07M | ﹤0.01% |
17,800
+16,300
| +1,087% | +$958K |
|
2563
CALL
Sanmina
SANM
$11.2B
| $1.07M | ﹤0.01% |
7,100
+5,400
| +318% | +$797K |
|
2564
PUT
Liberty Energy
LBRT
$2.83B
| $1.07M | ﹤0.01% |
57,700
-2,600
| -4% | -$43.4K |
|
2565
PUT
Amer Sports
AS
$19.7B
| $1.06M | ﹤0.01% |
28,500
+1,600
| +6% | +$54.9K |
|
2566
PUT
iQIYI
IQ
$1.18B
| $1.06M | ﹤0.01% |
554,200
-439,600
| -44% | -$941K |
|
2567
CALL
TransDigm Group
TDG
$69.2B
| $1.06M | ﹤0.01% |
800
-700
| -47% | -$918K |
|
2568
FMC
FMC
$1.42B
| $1.06M | ﹤0.01% |
76,672
+38,774
| +102% | +$739K |
|
2569
PUT
Array Technologies
ARRY
$818M
| $1.06M | ﹤0.01% |
115,300
-39,800
| -26% | -$341K |
|
|
2570
Liberty Energy
LBRT
$2.83B
| $1.06M | ﹤0.01% |
57,543
-36,664
| -39% | -$613K |
|
|
MRUS
2571
PUT
DELISTED
Merus
MRUS
| $1.06M | ﹤0.01% |
11,800
-13,600
| -54% | -$1.3M |
|
|
WRD
2572
PUT
WeRide Inc
WRD
$1.75B
| $1.06M | ﹤0.01% |
122,300
-260,600
| -68% | -$2.43M |
|
2573
PUT
Omega Healthcare
OHI
$15.4B
| $1.06M | ﹤0.01% |
23,900
-5,900
| -20% | -$254K |
|
2574
PUT
dLocal
DLO
$4.26B
| $1.06M | ﹤0.01% |
74,900
-34,100
| -31% | -$481K |
|
2575
PUT
Flowers Foods
FLO
$1.64B
| $1.06M | ﹤0.01% |
97,300
+82,500
| +557% | +$958K |
|
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.