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 | |
|---|---|---|---|---|---|---|
5676
CALL
ICL Group
ICL
$6.96B
| $105K | ﹤0.01% |
17,000
+11,900
| +233% | +$76.4K |
|
5677
PUT
Janux Therapeutics
JANX
$978M
| $105K | ﹤0.01% |
4,300
+1,900
| +79% | +$46.3K |
|
5678
CALL
NewtekOne
NEWT
$378M
| $105K | ﹤0.01% |
9,200
+1,500
| +19% | +$17.8K |
|
5679
PUT
Pacific Biosciences
PACB
$357M
| $105K | ﹤0.01% |
82,100
-27,300
| -25% | -$37K |
|
5680
PUT
Boston Beer
SAM
$1.9B
| $105K | ﹤0.01% |
500
-2,200
| -81% | -$468K |
|
5681
PUT
STAG Industrial
STAG
$7.12B
| $105K | ﹤0.01% |
3,000
-2,600
| -46% | -$92.7K |
|
5682
CALL
Cambria Tail Risk ETF
TAIL
$146M
| $105K | ﹤0.01% |
3,200
+2,500
| +357% | +$29.7K |
|
5683
CALL
Tompkins Financial
TMP
$1.45B
| $105K | ﹤0.01% |
1,600
+1,400
| +700% | +$93.8K |
|
5684
PUT
Tennant Co
TNC
$1.15B
| $105K | ﹤0.01% |
1,300
-1,500
| -54% | -$123K |
|
|
TRML
5685
CALL
DELISTED
Tourmaline Bio
TRML
| $105K | ﹤0.01% |
2,200
+2,000
| +1,000% | +$55.5K |
|
|
UPB
5686
CALL
Upstream Bio Inc
UPB
$378M
| $105K | ﹤0.01% |
+5,600
| New | +$87K |
|
5687
PUT
Applied Industrial Technologies
AIT
$13.2B
| $104K | ﹤0.01% |
400
-400
| -50% | -$105K |
|
5688
Alkami Technology
ALKT
$2.22B
| $104K | ﹤0.01% |
4,191
-22,262
| -84% | -$569K |
|
5689
Allegion
ALLE
$14.2B
| $104K | ﹤0.01% |
588
+8
| +1% | +$1.32K |
|
5690
Brookdale Senior Living
BKD
$3B
| $104K | ﹤0.01% |
12,350
-2,094
| -14% | -$16K |
|
5691
PUT
Camden National
CAC
$996M
| $104K | ﹤0.01% |
+2,700
| New | +$109K |
|
5692
PUT
Calix
CALX
$2.51B
| $104K | ﹤0.01% |
1,700
+600
| +55% | +$34.6K |
|
5693
CALL
Encore Capital Group
ECPG
$2.15B
| $104K | ﹤0.01% |
+2,500
| New | +$103K |
|
5694
CALL
Franklin Covey
FC
$227M
| $104K | ﹤0.01% |
5,400
+1,700
| +46% | +$33.6K |
|
5695
CALL
Gildan
GIL
$10.6B
| $104K | ﹤0.01% |
1,800
+500
| +38% | +$26.8K |
|
5696
CALL
Innovative Solutions & Support
ISSC
$407M
| $104K | ﹤0.01% |
8,400
+7,900
| +1,580% | +$110K |
|
5697
CALL
LivaNova
LIVN
$4.53B
| $104K | ﹤0.01% |
+2,000
| New | +$101K |
|
5698
Life Time Group Holdings
LTH
$9.9B
| $104K | ﹤0.01% |
3,784
-16,630
| -81% | -$474K |
|
5699
CALL
MidCap Financial Investment
MFIC
$811M
| $104K | ﹤0.01% |
8,700
-22,100
| -72% | -$282K |
|
5700
Principal Financial Group
PFG
$24.6B
| $104K | ﹤0.01% |
+1,255
| New | +$100K |
|
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.