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 | |
|---|---|---|---|---|---|---|
4526
CALL
BBB Foods
TBBB
$4.76B
| $150K | ﹤0.01% |
4,500
+3,100
| +221% | +$92.7K |
|
|
CRCO
4527
PUT
YieldMax CRCL Option Income Strategy ETF
CRCO
$17.6M
| $150K | ﹤0.01% |
+11,600
| New | +$406K |
|
4528
PUT
SandRidge Energy
SD
$503M
| $150K | ﹤0.01% |
10,400
-2,000
| -16% | -$26.5K |
|
4529
CALL
AllianceBernstein
AB
$3.47B
| $150K | ﹤0.01% |
3,900
-4,400
| -53% | -$174K |
|
4530
ABM Industries
ABM
$2.89B
| $150K | ﹤0.01% |
+3,547
| New | +$156K |
|
|
QIPT
4531
DELISTED
Quipt Home Medical
QIPT
| $150K | ﹤0.01% |
+42,475
| New | +$112K |
|
|
CMPS
4532
PUT
Compass Pathways
CMPS
$1.47B
| $150K | ﹤0.01% |
21,700
-40,700
| -65% | -$248K |
|
4533
CALL
XPEL
XPEL
$1.22B
| $150K | ﹤0.01% |
3,000
+200
| +7% | +$8.36K |
|
4534
CALL
Kodiak Gas Services
KGS
$5.55B
| $150K | ﹤0.01% |
4,000
-57,500
| -93% | -$2.03M |
|
4535
T-REX 2X Long Tesla Daily Target ETF
TSLT
$115M
| $149K | ﹤0.01% |
5,593
-13,732
| -71% | -$373K |
|
4536
PUT
Pegasystems
PEGA
$5.09B
| $149K | ﹤0.01% |
2,500
-3,700
| -60% | -$217K |
|
4537
Rocket Pharmaceuticals
RCKT
$343M
| $149K | ﹤0.01% |
+42,495
| New | +$145K |
|
4538
PUT
Expeditors International
EXPD
$22.3B
| $149K | ﹤0.01% |
1,000
+300
| +43% | +$40.8K |
|
4539
Heron Therapeutics
HRTX
$93.4M
| $149K | ﹤0.01% |
114,604
+87,734
| +327% | +$108K |
|
4540
CALL
Alto Ingredients
ALTO
$338M
| $149K | ﹤0.01% |
51,700
+15,600
| +43% | +$29.4K |
|
4541
PUT
Mineralys Therapeutics
MLYS
$2.32B
| $149K | ﹤0.01% |
4,100
-14,100
| -77% | -$565K |
|
4542
Ichor Holdings
ICHR
$2.17B
| $149K | ﹤0.01% |
+8,068
| New | +$150K |
|
4543
CALL
LendingTree
TREE
$551M
| $149K | ﹤0.01% |
2,800
-3,200
| -53% | -$179K |
|
|
BRSL
4544
PUT
Brightstar Lottery PLC
BRSL
$1.9B
| $149K | ﹤0.01% |
9,600
-13,300
| -58% | -$217K |
|
4545
CALL
Itron
ITRI
$4.48B
| $149K | ﹤0.01% |
1,600
+400
| +33% | +$43.6K |
|
4546
Ormat Technologies
ORA
$5.8B
| $148K | ﹤0.01% |
+1,342
| New | +$147K |
|
4547
Ryan Specialty Holdings
RYAN
$6.02B
| $148K | ﹤0.01% |
+2,868
| New | +$157K |
|
4548
CALL
MillerKnoll
MLKN
$1.56B
| $148K | ﹤0.01% |
8,100
-22,400
| -73% | -$365K |
|
4549
PUT
Golub Capital BDC
GBDC
$3.33B
| $148K | ﹤0.01% |
10,900
+4,900
| +82% | +$67.8K |
|
4550
CALL
O-I Glass
OI
$1.18B
| $148K | ﹤0.01% |
10,000
-16,500
| -62% | -$218K |
|
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.