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 | |
|---|---|---|---|---|---|---|
2776
PUT
Praxis Precision Medicines
PRAX
$9.07B
| $1.3M | ﹤0.01% |
24,600
-16,000
| -39% | -$776K |
|
2777
PUT
Community Health Systems
CYH
$385M
| $1.3M | ﹤0.01% |
405,900
-428,300
| -51% | -$1.29M |
|
|
FLY
2778
Firefly Aerospace
FLY
$3.23B
| $1.3M | ﹤0.01% |
+44,391
| New | +$2M |
|
2779
Pentair
PNR
$10.2B
| $1.3M | ﹤0.01% |
+11,744
| New | +$1.25M |
|
2780
Range Resources
RRC
$9.11B
| $1.3M | ﹤0.01% |
34,550
-5,453
| -14% | -$195K |
|
2781
Amgen
AMGN
$203B
| $1.3M | ﹤0.01% |
+4,602
| New | +$1.33M |
|
2782
CALL
Ametek
AME
$55.5B
| $1.3M | ﹤0.01% |
6,900
+4,600
| +200% | +$846K |
|
2783
Kura Oncology
KURA
$922M
| $1.29M | ﹤0.01% |
146,171
+141,962
| +3,373% | +$1.01M |
|
2784
CALL
BlackSky Technology
BKSY
$800M
| $1.29M | ﹤0.01% |
64,100
-10,000
| -13% | -$195K |
|
|
DFTX
2785
CALL
Definium Therapeutics
DFTX
$5.73B
| $1.29M | ﹤0.01% |
109,300
-9,100
| -8% | -$84.9K |
|
2786
CALL
First Trust Consumer Discretionary AlphaDEX Fund
FXD
$263M
| $1.29M | ﹤0.01% |
10,200
-10,500
| -51% | -$704K |
|
2787
PUT
GXO Logistics
GXO
$6.06B
| $1.28M | ﹤0.01% |
24,300
-64,800
| -73% | -$3.33M |
|
2788
CALL
Melco Resorts & Entertainment
MLCO
$2.1B
| $1.28M | ﹤0.01% |
140,100
+16,600
| +13% | +$152K |
|
|
MFA
2789
PUT
MFA Financial
MFA
$929M
| $1.28M | ﹤0.01% |
139,700
+83,100
| +147% | +$803K |
|
2790
Frontline
FRO
$8.75B
| $1.28M | ﹤0.01% |
56,294
+20,758
| +58% | +$420K |
|
2791
CALL
PVH
PVH
$3.71B
| $1.28M | ﹤0.01% |
15,300
-40,700
| -73% | -$3.2M |
|
2792
PUT
GigaCloud Technology
GCT
$1.35B
| $1.28M | ﹤0.01% |
45,100
+35,800
| +385% | +$934K |
|
2793
PUT
Ginkgo Bioworks
DNA
$481M
| $1.28M | ﹤0.01% |
87,700
+13,100
| +18% | +$157K |
|
2794
PUT
Rapid7
RPD
$634M
| $1.28M | ﹤0.01% |
68,200
-19,800
| -23% | -$418K |
|
2795
CALL
Regal Rexnord
RRX
$14.2B
| $1.28M | ﹤0.01% |
8,900
+7,800
| +709% | +$1.15M |
|
2796
FMC
FMC
$1.42B
| $1.27M | ﹤0.01% |
37,898
-3,229
| -8% | -$126K |
|
2797
PUT
Tronox
TROX
$995M
| $1.27M | ﹤0.01% |
316,500
+314,200
| +13,661% | +$1.44M |
|
|
CEP
2798
CALL
DELISTED
Cantor Equity Partners
CEP
| $1.27M | ﹤0.01% |
56,800
-17,900
| -24% | -$466K |
|
2799
Lufax Holding
LU
$1.2B
| $1.27M | ﹤0.01% |
312,510
+245,087
| +364% | +$732K |
|
2800
CALL
Sigma Lithium
SGML
$1.08B
| $1.27M | ﹤0.01% |
197,900
+152,200
| +333% | +$915K |
|
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.