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 |
Microsoft
MSFT
|
+$234M |
| 2 |
iShares Russell 2000 ETF
IWM
|
+$97.5M |
| 3 |
Amazon
AMZN
|
+$96.8M |
| 4 |
iShares Bitcoin Trust
IBIT
|
+$80.6M |
| 5 |
Pinduoduo
PDD
|
+$54.9M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
iShares 20+ Year Treasury Bond ETF
TLT
|
+$129M |
| 2 |
Alphabet (Google) Class A
GOOGL
|
+$92.9M |
| 3 |
Broadcom
AVGO
|
+$82.9M |
| 4 |
Alphabet (Google) Class C
GOOG
|
+$68.4M |
| 5 |
Meta Platforms (Facebook)
META
|
+$59.2M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 0.79% |
| 2 | Consumer Discretionary | 0.3% |
| 3 | Healthcare | 0.25% |
| 4 | Financials | 0.17% |
| 5 | Industrials | 0.09% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
4401
Leonardo DRS
DRS
$12.4B
| $311K | ﹤0.01% |
+6,854
| New | +$299K |
|
|
PLG
4402
Platinum Group Metals
PLG
$160M
| $311K | ﹤0.01% |
117,623
+10,271
| +10% | +$17.5K |
|
4403
PUT
Cactus
WHD
$3.63B
| $311K | ﹤0.01% |
7,900
+6,700
| +558% | +$282K |
|
4404
CALL
CG Oncology
CGON
$6.1B
| $310K | ﹤0.01% |
7,700
-3,300
| -30% | -$95.9K |
|
4405
PUT
Check Point Software Technologies
CHKP
$14.3B
| $310K | ﹤0.01% |
1,500
-100
| -6% | -$20.2K |
|
4406
CryoPort
CYRX
$753M
| $310K | ﹤0.01% |
32,800
+6,546
| +25% | +$55.1K |
|
4407
CALL
Gray Television
GTN
$437M
| $310K | ﹤0.01% |
53,700
+47,100
| +714% | +$256K |
|
4408
M/I Homes
MHO
$3.95B
| $310K | ﹤0.01% |
+2,147
| New | +$290K |
|
4409
Riskified
RSKD
$719M
| $310K | ﹤0.01% |
+66,278
| New | +$326K |
|
4410
CALL
Sundial Growers
SNDL
$312M
| $310K | ﹤0.01% |
115,800
-89,000
| -43% | -$179K |
|
|
WBTN
4411
CALL
WEBTOON Entertainment Inc
WBTN
$1.22B
| $310K | ﹤0.01% |
+16,000
| New | +$213K |
|
|
WBTN
4412
WEBTOON Entertainment Inc
WBTN
$1.22B
| $310K | ﹤0.01% |
15,974
+15,840
| +11,821% | +$211K |
|
|
VOYG
4413
Voyager Technologies
VOYG
$1.34B
| $310K | ﹤0.01% |
10,440
+7,993
| +327% | +$276K |
|
4414
Fox Class B
FOX
$22.1B
| $309K | ﹤0.01% |
5,400
+5,339
| +8,752% | +$282K |
|
4415
Invesco CurrencyShares Swiss Franc Trust
FXF
$411M
| $309K | ﹤0.01% |
2,785
+1,457
| +110% | +$161K |
|
4416
MediWound
MDWD
$184M
| $309K | ﹤0.01% |
17,189
+16,205
| +1,647% | +$299K |
|
4417
PUT
Spire Global
SPIR
$408M
| $309K | ﹤0.01% |
28,200
-12,000
| -30% | -$124K |
|
4418
CALL
Avanos Medical
AVNS
| $308K | ﹤0.01% |
+26,700
| New | +$313K |
|
4419
BioCryst Pharmaceuticals
BCRX
$2.42B
| $308K | ﹤0.01% |
40,602
+29,118
| +254% | +$242K |
|
|
DAWN
4420
CALL
DELISTED
Day One Biopharmaceuticals
DAWN
| $308K | ﹤0.01% |
43,700
+35,100
| +408% | +$242K |
|
4421
Delek US
DK
$3.98B
| $308K | ﹤0.01% |
9,548
-2,621
| -22% | -$68.5K |
|
4422
CALL
Kirby Corp
KEX
$7.01B
| $308K | ﹤0.01% |
3,700
+3,600
| +3,600% | +$362K |
|
4423
Klaviyo
KVYO
$5.8B
| $308K | ﹤0.01% |
11,147
+9,693
| +667% | +$313K |
|
4424
CALL
Woodside Energy
WDS
$44.2B
| $308K | ﹤0.01% |
20,500
+4,800
| +31% | +$79.1K |
|
|
RIOX
4425
Defiance Daily Target 2X Long RIOT ETF
RIOX
$12.2M
| $308K | ﹤0.01% |
3,070
+2,778
| +951% | +$168K |
|
Similar funds
Simplex Trading's Q3 2025 Portfolio in Review
As of Q3 2025, Simplex Trading held 10,358 positions worth $195B, up 12% from $175B the previous quarter. Its ten largest holdings account for 46% of the portfolio.
Simplex Trading's Q3 2025 filing shows 1,743 new, 3,828 increased, 3,250 reduced and 1,308 closed positions. Its largest new stake was Microsoft: 458,309 shares worth $237M. The largest sale was iShares 20+ Year Treasury Bond ETF, an estimated $129M.
By sector, the portfolio is most concentrated in Technology at 0.79% of assets, up from 0.74% a quarter earlier, followed by Consumer Discretionary and Healthcare.
- Simplex Trading's largest Q3 2025 buy was Microsoft: 458,309 shares worth $237M.
- Simplex Trading added most to iShares Russell 2000 ETF in Q3 2025, an estimated $97.5M increase.
- Simplex Trading's biggest Q3 2025 reduction was Alphabet (Google) Class A, cutting an estimated $92.9M.
- Simplex Trading fully exited iShares 20+ Year Treasury Bond ETF in Q3 2025, selling an estimated $129M.
- Simplex Trading's ten largest holdings make up 46% of its $195B portfolio in Q3 2025.
- Simplex Trading opened 1,743 new positions and closed 1,308 in Q3 2025.
- Simplex Trading's portfolio value rose 12% quarter-over-quarter to $195B.
Based on Simplex Trading's 13F filing for Q3 2025, filed 12 Nov 2025.