Period
Q2 2025
Calendar quarter covered by the filing.
CSS LLC/IL portfolio
Q2 2025 · Holdings as of · Filed · reported in Form 13F
$1.58B
Full value: $1,580,351,072 · USD · 30 Jun 2025What changed in Q2 2025?
Comparable share positions since Q1 2025.
- New
- 172
- Increased
- 166
- Reduced
- 171
- Exited
- 134
9 positions with incomplete comparison or price data excluded.
Largest disclosed changes
-
shares
-42.47K
Full value: -42,470 · shares · 30 Jun 2025estimated-$35.16M
Full value: -$35,162,612 · USD · 30 Jun 2025 · Estimated from share changes and filing pricesWeight -1.48 percentage points
-
shares
+400.47K
Full value: +400,466 · shares · 30 Jun 2025estimated+$33.03M
Full value: +$33,034,521 · USD · 30 Jun 2025 · Estimated from share changes and filing pricesWeight +2.09 percentage points
-
shares
+756.5K
Full value: +756,498 · shares · 30 Jun 2025estimated+$30.1M
Full value: +$30,095,684 · USD · 30 Jun 2025 · Estimated from share changes and filing pricesWeight +1.9 percentage points
-
shares
+18.53K
Full value: +18,529 · shares · 30 Jun 2025estimated+$22.42M
Full value: +$22,420,572 · USD · 30 Jun 2025 · Estimated from share changes and filing pricesWeight +1.42 percentage points
-
shares
-38.58K
Full value: -38,580 · shares · 30 Jun 2025estimated-$21.91M
Full value: -$21,914,596 · USD · 30 Jun 2025 · Estimated from share changes and filing pricesWeight -1.38 percentage points
Estimates use share changes and filing prices. They are not trade proceeds. Options and principal positions are excluded.
Compare with Q1 2025Holdings
| Sym | Weight | Trade Impact | Company | Class | Share Change | Activity | Value change | SEC-reported value | SEC-reported price | Shares | Principal |
|---|
Filing details and SEC source
- Portfolio date
- 30 Jun 2025
- Reported 13F value
- $1,580,351,072
- Reported 13F holdings
- 673
- What this filing covers
-
13F holdings
673Parsed equity rows, excluding option-only view rows.
Reported value
$1,580,351,072SEC Form 13F market value, not total AUM.
Accepted by SEC
14 Aug 2025EDGAR acceptance date.
How to read this filing
- Start with the largest positions and changes, then open issuer-level rows for CUSIP-specific history.
- Form 13F market value excludes cash and many non-13F assets, so it should not be treated as total assets under management.
- SEC classifies this as a holdings report: this manager reports its visible U.S.-listed equity holdings in this filing.
- Largest 13F holdings
-
STRIDE INC IONIS PHARMACEUTICALS INC JAZZ INVESTMENTS I LTD SHIFT4 PMTS INC SEAGATE HDD CAYMAN BTSGU MARRIOTT VACATIONS WORLDWIDE MICROSTRATEGY INC NEEPRR IMAX CORP SNAP INC UBER TECHNOLOGIES INC
+7 more
BANK AMERICA CORP TRANSOCEAN INC PEABODY ENGR CORP TRAVERE THERAPEUTICS INC WAYFAIR INC WEC ENERGY GROUP INC PTC THERAPEUTICS INC - Manager signature
- Mitchel Bialek - CCO
- Manager location
- Chicago, IL
- Accepted by SEC
- 14 Aug 2025, 15:44:07 UTC
- SEC form
- 13F-HR
- Prior SEC filing
- Q1 2025 - 15 May 2025
- Next SEC filing
- Q3 2025 - 13 Nov 2025
- Source filing
- View source filing
- Options holdings
- Showing equity holdings. Open options holdings.
13F snapshot
Latest parsed holdings, value, and filing-period context.
2 signals
Manager
Names, identifiers, and filing context for this profile.
2 identity fields
Source evidence
Original filing metadata and source links for verification.
5 source fields
Related views
1 detail
This view compares filing 2025 Q2 with 2025 Q1. Changes are calculated against the previous SEC filing.
SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held.
* marks a reported price that did not pass the local price check.
* marks a reported price that did not pass the local price check.
Person Signing this Report on Behalf of Reporting Manager:
| Name | Title | City, State | Date |
|---|---|---|---|
| Mitchel Bialek | CCO | Chicago, Illinois | 14 Aug 2025 |