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 | |
|---|---|---|---|---|---|---|
3526
State Street SPDR S&P Oil & Gas Exploration & Production ETF
XOP
$3.42B
| $644K | ﹤0.01% |
+4,878
| New | +$630K |
|
|
MFA
3527
MFA Financial
MFA
$935M
| $642K | ﹤0.01% |
69,942
+41,240
| +144% | +$398K |
|
3528
PUT
SGHC Ltd
SGHC
$7.62B
| $642K | ﹤0.01% |
+48,700
| New | +$573K |
|
3529
Enova International
ENVA
$6.2B
| $640K | ﹤0.01% |
5,561
+5,537
| +23,071% | +$633K |
|
3530
PUT
BioCryst Pharmaceuticals
BCRX
$2.48B
| $639K | ﹤0.01% |
84,200
-22,600
| -21% | -$188K |
|
3531
CALL
Trinity Industries
TRN
$3.03B
| $639K | ﹤0.01% |
22,800
+21,600
| +1,800% | +$596K |
|
3532
PUT
B&G Foods
BGS
$297M
| $638K | ﹤0.01% |
144,200
-45,200
| -24% | -$197K |
|
3533
CALL
Xerox
XRX
$360M
| $638K | ﹤0.01% |
169,700
+43,800
| +35% | +$194K |
|
3534
PUT
Neogen
NEOG
$2B
| $637K | ﹤0.01% |
111,700
| – | – |
|
|
SA
3535
PUT
Seabridge Gold
SA
$2.69B
| $637K | ﹤0.01% |
26,400
-9,500
| -26% | -$164K |
|
|
BLDP
3536
Ballard Power Systems
BLDP
$808M
| $636K | ﹤0.01% |
233,878
+215,830
| +1,196% | +$442K |
|
3537
CALL
Lennox International
LII
$18.9B
| $635K | ﹤0.01% |
1,200
+100
| +9% | +$58.4K |
|
3538
CALL
BRC Group Holdings
RILY
$270M
| $635K | ﹤0.01% |
106,300
+24,400
| +30% | +$135K |
|
3539
Velocity Financial
VEL
$698M
| $635K | ﹤0.01% |
35,050
-18,822
| -35% | -$344K |
|
|
MRX
3540
PUT
Marex Group Limited Ordinary Shares
MRX
$4.62B
| $635K | ﹤0.01% |
18,900
+17,000
| +895% | +$614K |
|
3541
ClearPoint Neuro
CLPT
$436M
| $634K | ﹤0.01% |
+29,100
| New | +$343K |
|
3542
PUT
Plains GP Holdings
PAGP
$5.2B
| $634K | ﹤0.01% |
34,800
-45,500
| -57% | -$869K |
|
3543
Kosmos Energy
KOS
$1.39B
| $632K | ﹤0.01% |
380,961
-217,687
| -36% | -$407K |
|
3544
PUT
Nexstar Media Group
NXST
$5.92B
| $632K | ﹤0.01% |
3,200
+2,100
| +191% | +$411K |
|
3545
CALL
Neurocrine Biosciences
NBIX
$18.4B
| $631K | ﹤0.01% |
4,500
-2,000
| -31% | -$271K |
|
3546
PUT
Fortuna Silver Mines
FSM
$2.55B
| $630K | ﹤0.01% |
70,400
+4,800
| +7% | +$35K |
|
3547
CALL
Marqeta
MQ
$1.9B
| $630K | ﹤0.01% |
29,875
+4,025
| +16% | +$95.4K |
|
3548
Replimune Group
REPL
$449M
| $630K | ﹤0.01% |
150,446
+111,900
| +290% | +$715K |
|
3549
CALL
Teradata
TDC
$2.75B
| $630K | ﹤0.01% |
29,300
-42,800
| -59% | -$921K |
|
3550
CALL
Unum
UNM
$14B
| $630K | ﹤0.01% |
8,100
+2,500
| +45% | +$187K |
|
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.