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 | |
|---|---|---|---|---|---|---|
4701
PUT
SES AI
SES
$187M
| $245K | ﹤0.01% |
146,800
+57,000
| +63% | +$68.2K |
|
|
DENN
4702
PUT
DELISTED
Denny's
DENN
| $244K | ﹤0.01% |
46,800
+18,400
| +65% | +$81.6K |
|
4703
CALL
Zurn Elkay Water Solutions
ZWS
$8.55B
| $244K | ﹤0.01% |
+5,200
| New | +$224K |
|
4704
PUT
Immunovant
IMVT
$7.93B
| $243K | ﹤0.01% |
15,100
+10,600
| +236% | +$172K |
|
|
XXRP
4705
Teucrium 2x Long Daily XRP ETF
XXRP
$89M
| $243K | ﹤0.01% |
753
-171
| -19% | -$68.2K |
|
|
AIRL
4706
CALL
DELISTED
Themes Airlines ETF
AIRL
| $242K | ﹤0.01% |
10,500
+10,100
| +2,525% | +$340K |
|
4707
PUT
Allot
ALLT
$362M
| $242K | ﹤0.01% |
22,900
-122,400
| -84% | -$1.04M |
|
4708
BlackSky Technology
BKSY
$843M
| $242K | ﹤0.01% |
12,052
+11,710
| +3,424% | +$228K |
|
4709
Erasca
ERAS
$6.15B
| $242K | ﹤0.01% |
111,337
+78,690
| +241% | +$125K |
|
4710
Federal Realty Investment Trust
FRT
$10.9B
| $242K | ﹤0.01% |
+2,393
| New | +$231K |
|
4711
PUT
Genmab
GMAB
$17.5B
| $242K | ﹤0.01% |
7,900
-18,300
| -70% | -$446K |
|
4712
PUT
Gaotu Techedu
GOTU
$405M
| $242K | ﹤0.01% |
74,400
-14,500
| -16% | -$52.7K |
|
4713
Navios Maritime Partners
NMM
$2.22B
| $242K | ﹤0.01% |
5,391
+575
| +12% | +$25.5K |
|
4714
CALL
Warby Parker
WRBY
$3.19B
| $242K | ﹤0.01% |
8,800
-19,100
| -68% | -$483K |
|
|
4715
CALL
Immunovant
IMVT
$7.93B
| $241K | ﹤0.01% |
15,000
-13,900
| -48% | -$225K |
|
4716
Transmedics
TMDX
$2.7B
| $241K | ﹤0.01% |
2,151
-13,998
| -87% | -$1.64M |
|
4717
PUT
Camping World
CWH
$384M
| $240K | ﹤0.01% |
15,200
+10,100
| +198% | +$173K |
|
|
4718
Immunovant
IMVT
$7.93B
| $240K | ﹤0.01% |
14,932
+10,126
| +211% | +$164K |
|
4719
CALL
iRhythm Holdings
IRTC
$4.02B
| $240K | ﹤0.01% |
1,400
+600
| +75% | +$95.4K |
|
|
PCH
4720
PUT
DELISTED
PotlatchDeltic
PCH
| $240K | ﹤0.01% |
5,900
+4,600
| +354% | +$191K |
|
4721
Zevra Therapeutics
ZVRA
$578M
| $240K | ﹤0.01% |
+25,328
| New | +$254K |
|
4722
CALL
China Yuchai International
CYD
$1.69B
| $239K | ﹤0.01% |
5,800
+2,700
| +87% | +$81.6K |
|
4723
CALL
Exagen
XGN
$105M
| $239K | ﹤0.01% |
21,800
+16,700
| +327% | +$148K |
|
|
MNTN
4724
PUT
MNTN Inc
MNTN
$707M
| $239K | ﹤0.01% |
12,900
+12,800
| +12,800% | +$291K |
|
4725
CALL
Capital Southwest
CSWC
$1.47B
| $238K | ﹤0.01% |
10,900
-100
| -0.9% | -$2.28K |
|
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.