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 |
Netflix
NFLX
|
+$73.1M |
| 2 |
Western Digital
WDC
|
+$51.8M |
| 3 |
iShares Semiconductor ETF
SOXX
|
+$46M |
| 4 |
Meta Platforms (Facebook)
META
|
+$41.8M |
| 5 |
Alibaba
BABA
|
+$37.1M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
NVIDIA
NVDA
|
+$262M |
| 2 |
Microsoft
MSFT
|
+$194M |
| 3 |
iShares Russell 2000 ETF
IWM
|
+$149M |
| 4 |
Apple
AAPL
|
+$119M |
| 5 |
Amazon
AMZN
|
+$107M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Miscellaneous | 98.27% |
| 2 | Technology | 0.59% |
| 3 | Consumer Discretionary | 0.21% |
| 4 | Healthcare | 0.2% |
| 5 | Industrials | 0.18% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | Held Since | |
|---|---|---|---|---|---|---|---|
1
PUT
State Street SPDR S&P 500 ETF Trust
SPY
$815B
| $28.1B | 15.86% |
41,254,200
-5,486,600
| -12% | -$3.71B |
2015 Q1
43 quarters
|
|
|
2
CALL
State Street SPDR S&P 500 ETF Trust
SPY
$815B
| $13.3B | 7.47% |
19,433,600
+1,056,700
| +6% | +$714M |
2015 Q1
43 quarters
|
|
3
PUT
Invesco QQQ Trust
QQQ
$475B
| $9.44B | 5.32% |
15,365,400
-3,586,900
| -19% | -$2.2B |
2021 Q2
18 quarters
|
|
|
4
CALL
Invesco QQQ Trust
QQQ
$475B
| $5.86B | 3.3% |
9,538,600
+1,557,100
| +20% | +$955M |
2021 Q2
18 quarters
|
|
5
PUT
Tesla
TSLA
$1.48T
| $5.78B | 3.26% |
12,842,700
+343,600
| +3% | +$152M |
2021 Q2
18 quarters
|
|
6
PUT
iShares S&P 100 ETF
OEF
$20.3B
| $5.48B | 3.09% |
33,557,500
-5,424,700
| -14% | -$1.84B |
2014 Q4
44 quarters
|
|
|
7
CALL
NVIDIA
NVDA
$5.12T
| $5.35B | 3.02% |
28,686,200
+2,823,200
| +11% | +$526M |
2021 Q2
18 quarters
|
|
|
8
CALL
Tesla
TSLA
$1.48T
| $5.26B | 2.96% |
11,691,000
+241,500
| +2% | +$107M |
2021 Q2
18 quarters
|
|
|
9
PUT
NVIDIA
NVDA
$5.12T
| $4.92B | 2.77% |
26,359,200
-1,091,900
| -4% | -$203M |
2021 Q2
18 quarters
|
|
|
10
CALL
iShares S&P 100 ETF
OEF
$20.3B
| $3.55B | 2% |
26,135,800
-3,228,100
| -11% | -$1.1B |
2014 Q4
44 quarters
|
|
|
11
CALL
Meta Platforms (Facebook)
META
$1.65T
| $3.04B | 1.71% |
4,605,900
+1,537,600
| +50% | +$1.03B |
2014 Q4
44 quarters
|
|
12
CALL
Alphabet (Google) Class A
GOOGL
$3.97T
| $2.8B | 1.58% |
8,944,200
-939,700
| -10% | -$269M |
2015 Q4
40 quarters
|
|
13
CALL
SPDR Gold Trust
GLD
$136B
| $2.54B | 1.43% |
6,421,700
-620,700
| -9% | -$237M |
2015 Q1
43 quarters
|
|
|
14
CALL
Apple
AAPL
$5.08T
| $2.52B | 1.42% |
9,285,900
-491,900
| -5% | -$132M |
2015 Q1
43 quarters
|
|
|
15
PUT
Alphabet (Google) Class A
GOOGL
$3.97T
| $2.3B | 1.3% |
7,357,300
+483,600
| +7% | +$138M |
2015 Q4
40 quarters
|
|
|
16
PUT
Apple
AAPL
$5.08T
| $2.11B | 1.19% |
7,745,900
-2,012,300
| -21% | -$540M |
2015 Q1
43 quarters
|
|
|
17
PUT
SPDR Gold Trust
GLD
$136B
| $1.65B | 0.93% |
4,151,600
-1,847,600
| -31% | -$706M |
2015 Q1
43 quarters
|
|
|
18
PUT
Meta Platforms (Facebook)
META
$1.65T
| $1.6B | 0.9% |
2,425,600
+208,600
| +9% | +$139M |
2014 Q4
44 quarters
|
|
|
19
CALL
Microsoft
MSFT
$3.87T
| $1.49B | 0.84% |
3,087,200
-556,000
| -15% | -$279M |
2014 Q4
44 quarters
|
|
|
20
CALL
Amazon
AMZN
$2.7T
| $1.35B | 0.76% |
5,860,700
-2,298,800
| -28% | -$526M |
2015 Q1
43 quarters
|
|
21
PUT
Broadcom
AVGO
$1.54T
| $1.27B | 0.71% |
3,657,900
+612,200
| +20% | +$219M |
2021 Q2
18 quarters
|
|
22
PUT
State Street Materials Select Sector SPDR ETF
XLB
$8.18B
| $1.17B | 0.66% |
16,781,100
-14,322,700
| -46% | -$633M |
2015 Q1
43 quarters
|
|
23
CALL
iShares Silver Trust
SLV
$26.6B
| $1.15B | 0.65% |
17,904,900
-2,194,800
| -11% | -$110M |
2021 Q2
18 quarters
|
|
24
CALL
Palantir
PLTR
$471B
| $1.1B | 0.62% |
6,167,100
+1,200,500
| +24% | +$217M |
2021 Q2
18 quarters
|
|
|
25
PUT
Microsoft
MSFT
$3.87T
| $1.08B | 0.61% |
2,243,400
-904,600
| -29% | -$453M |
2014 Q4
44 quarters
|
|
Similar funds
Simplex Trading's Q4 2025 Portfolio in Review
As of Q4 2025, Simplex Trading held 10,526 positions worth $177B, down 9% from $195B the previous quarter. Its ten largest holdings account for 49% of the portfolio.
Simplex Trading's Q4 2025 filing shows 1,476 new, 2,599 increased, 4,088 reduced and 2,184 closed positions. Its largest new stake was Western Digital: 341,762 shares worth $58.9M. The largest sale was NVIDIA, an estimated $262M.
By sector, the portfolio is most concentrated in Miscellaneous at 98% of assets, up from 98% a quarter earlier, followed by Technology and Consumer Discretionary.
- Simplex Trading's largest Q4 2025 buy was Western Digital: 341,762 shares worth $58.9M.
- Simplex Trading added most to Netflix in Q4 2025, an estimated $73.1M increase.
- Simplex Trading's biggest Q4 2025 reduction was NVIDIA, cutting an estimated $262M.
- Simplex Trading fully exited iShares Russell 2000 ETF in Q4 2025, selling an estimated $149M.
- Simplex Trading's ten largest holdings make up 49% of its $177B portfolio in Q4 2025.
- Simplex Trading opened 1,476 new positions and closed 2,184 in Q4 2025.
- Simplex Trading's portfolio value fell 9% quarter-over-quarter to $177B.
Based on Simplex Trading's 13F filing for Q4 2025, filed 11 Feb 2026.