Period
Q1 2025
Calendar quarter covered by the filing.
CSS LLC/IL portfolio
Q1 2025 · Holdings as of · Filed · $1,433,875,508 reported in Form 13F
What changed in Q1 2025?
Comparable share positions since Q4 2024.
- New
- 134
- Increased
- 178
- Reduced
- 160
- Exited
- 127
6 positions with incomplete comparison or price data excluded.
Largest disclosed changes
-
-596,989 shares
-$33,055,102 estimated
Weight -2.57 percentage points
-
-226,997 shares
-$29,489,181 estimated
Weight -1.76 percentage points
-
47,404 shares
+$24,932,134 estimated
Weight +1.74 percentage points
-
-289,212 shares
-$21,238,833 estimated
Weight -1.52 percentage points
-
-286,141 shares
-$19,780,956 estimated
Weight -1.18 percentage points
Estimates use share changes and filing prices. They are not trade proceeds. Options and principal positions are excluded.
Compare with Q4 2024Holdings
| 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
- 31 Mar 2025
- Reported 13F value
- $1,433,875,508
- Reported 13F holdings
- 630
- What this filing covers
-
13F holdings
630Parsed equity rows, excluding option-only view rows.
Reported value
$1,433,875,508SEC Form 13F market value, not total AUM.
Accepted by SEC
15 May 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
-
AMERICAN AIRLINES GROUP INC STRIDE INC INSMED INC JAZZ INVESTMENTS I LTD IONIS PHARMACEUTICALS INC PENN ENTERTAINMENT INC VOO MARRIOTT VACATIONS WORLDWIDE PEABODY ENGR CORP AXON SOUTHWEST AIRLS CO IMAX CORP
+8 more
SHIFT4 PMTS INC VENTAS RLTY LTD PARTNERSHIP MICROSTRATEGY INC TRAVERE THERAPEUTICS INC SNAP INC ALLIANT ENERGY CORP KIMPRN RSP - Manager signature
- Mitchel Bialek - CCO
- Manager location
- Chicago, IL
- Accepted by SEC
- 15 May 2025, 15:55:33 UTC
- SEC form
- 13F-HR
- Prior SEC filing
- Q4 2024 - 18 Feb 2025
- Next SEC filing
- Q2 2025 - 14 Aug 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 Q1 with 2024 Q4. 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 | 15 May 2025 |