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 | |
|---|---|---|---|---|---|---|
2526
CALL
Cal-Maine
CALM
$4.28B
| $1.11M | ﹤0.01% |
14,000
-10,200
| -42% | -$896K |
|
|
APLS
2527
PUT
DELISTED
Apellis Pharmaceuticals
APLS
| $1.11M | ﹤0.01% |
44,300
-100
| -0.2% | -$2.35K |
|
2528
CALL
Red Rock Resorts
RRR
$3.74B
| $1.11M | ﹤0.01% |
17,900
-9,100
| -34% | -$532K |
|
2529
CALL
Endava
DAVA
$141M
| $1.11M | ﹤0.01% |
175,400
+171,300
| +4,178% | +$1.31M |
|
2530
PUT
Ball Corp
BALL
$17B
| $1.11M | ﹤0.01% |
20,900
-7,300
| -26% | -$359K |
|
2531
PUT
Bio-Techne
TECH
$11.2B
| $1.11M | ﹤0.01% |
18,800
+3,400
| +22% | +$207K |
|
2532
PUT
Semtech
SMTC
$11.7B
| $1.11M | ﹤0.01% |
15,000
-3,600
| -19% | -$255K |
|
|
TWO
2533
PUT
Two Harbors Investment
TWO
$1.27B
| $1.1M | ﹤0.01% |
105,200
-122,700
| -54% | -$1.23M |
|
2534
CALL
Schrodinger
SDGR
$1.12B
| $1.1M | ﹤0.01% |
61,700
-900
| -1% | -$17.1K |
|
2535
PUT
Murphy Oil
MUR
$5.58B
| $1.1M | ﹤0.01% |
35,300
-91,900
| -72% | -$2.76M |
|
2536
Direxion Daily 20+ Year Treasury Bear 3X ETF
TMV
$180M
| $1.1M | ﹤0.01% |
+29,653
| New | +$1.03M |
|
2537
Entegris
ENTG
$19.7B
| $1.1M | ﹤0.01% |
13,052
+9,551
| +273% | +$830K |
|
|
SOLS
2538
PUT
Solstice Advanced Materials
SOLS
$9.62B
| $1.1M | ﹤0.01% |
+22,600
| New | +$1.06M |
|
2539
PUT
Invitation Homes
INVH
$17.7B
| $1.1M | ﹤0.01% |
39,500
+8,300
| +27% | +$232K |
|
2540
CALL
MaxLinear
MXL
$6.49B
| $1.1M | ﹤0.01% |
62,900
+28,400
| +82% | +$462K |
|
2541
PUT
Patterson-UTI
PTEN
$3.87B
| $1.1M | ﹤0.01% |
179,400
-114,200
| -39% | -$682K |
|
2542
PUT
J.M. Smucker
SJM
$12.6B
| $1.1M | ﹤0.01% |
11,200
+1,900
| +20% | +$196K |
|
2543
ATI
ATI
$27B
| $1.1M | ﹤0.01% |
9,545
+4,585
| +92% | +$447K |
|
2544
Vanguard World Funds Extended Duration ETF
EDV
$3.3B
| $1.09M | ﹤0.01% |
16,843
+12,273
| +269% | +$835K |
|
2545
PUT
Vista Energy
VIST
$7.75B
| $1.09M | ﹤0.01% |
22,500
-137,900
| -86% | -$6.23M |
|
2546
PUT
Icon
ICLR
$12.8B
| $1.09M | ﹤0.01% |
6,000
+600
| +11% | +$107K |
|
2547
PUT
Williams Companies
WMB
$90.5B
| $1.09M | ﹤0.01% |
18,100
-36,000
| -67% | -$2.18M |
|
2548
CALL
Canadian National Railway
CNI
$78.3B
| $1.09M | ﹤0.01% |
11,000
-39,000
| -78% | -$3.75M |
|
|
SAFE
2549
PUT
Safehold
SAFE
$1.19B
| $1.09M | ﹤0.01% |
79,400
+77,100
| +3,352% | +$1.1M |
|
2550
JB Hunt Transport Services
JBHT
$27.1B
| $1.09M | ﹤0.01% |
+5,593
| New | +$960K |
|
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.