2026-Q1 CITADEL ADVISORS LLC 13F Filing: Citadel boosted SPY by +$2.50B in Q1

A 13F filing reveals the U.S.-listed equity holdings of a large institutional manager at the end of a calendar quarter, offering a snapshot of their long positions. In its first-quarter 2026 report, Citadel Advisors LLC increased its holding count to 6,733 and rotated among sectors, with Information Technology swelling to 35.2% of the portfolio from 34.6% three months earlier.

1. What a 13F filing actually discloses – It shows only long equity positions (no short bets or derivatives) held on the quarter's final day. Citadel managed a portfolio with a turnover ratio of 0.34 and an HHI concentration of 0.015, meaning it held thousands of positions spread broadly. The sector weights alone tell you where the fund made its biggest bets: Information Technology (35.2% of the portfolio), Consumer Discretionary (15.2%), and Communication Services (11.2%) were the largest.

2. How to spot a genuine increase vs. a decrease – Every position in a 13F carries an “action” that tells you exactly what the manager did. An “add” means the fund bought more shares; a “trim” means it sold some; a “sold_out” means it liquidated the entire stake. Among the largest moves, Citadel added to SPY (+$2.50B), MU (+$4.01B), SNDK (+$3.45B), and GLD (+$2.30B). Each of these grew in both share count and dollar value. But sometimes the action and the value move in opposite directions—see point 4.

3. How to read a trim – When a fund trims a position, it reduces its share count but still owns the stock. Citadel trimmed many of its top mega-cap names: TSLA fell by -$10.75B, NVDA by -$4.89B, and QQQ by -$4.44B. Portfolio weights for TSLA dropped from 5.18% to 3.84%, and for NVDA from 4.33% to 3.87%. The fund also made outright exits from some smaller positions (a full “sold_out” line would show zero shares), but in this filing most changes were trims or adds.

4. When the dollar value contradicts the action – Occasionally the number of shares increases yet the total market value falls, creating a row that looks like a “sell” when it was actually a buy. Citadel added to META (action: add) but the dollar value fell by -$2.09B. According to the filing’s own note, “shares were added (real buying), but the dollar value fell because the stock price dropped more than the added shares were worth – NOT a sell.” The same pattern appears for APP: an add with a dollar drop of -$954.2M. Ignoring the note would make these look like trims; the note clarifies they were actually accumulations.

5. What “unchanged” means and doesn’t mean – A holding labeled “unchanged” means Citadel did not touch the share count during the quarter. Any change in portfolio weight or dollar value for that holding is purely due to the stock’s price movement, not to any decision by the manager. While the top changes list here contains only active moves, many of the fund’s 6,733 holdings fell into the “unchanged” category – their value drift is passive and doesn’t reflect a trading opinion.

6. The overall pattern of the quarter’s moves – Citadel trimmed mega-cap growth stocks (TSLA, NVDA, AMZN, AAPL) while adding to value-oriented sectors such as energy (XOM, CVX), materials (EEM), and gold (GLD). It also boosted its weighting in the S&P 500 through SPY and used the volatility to build positions in semiconductor names like MU and SNDK. The turnover ratio rose from 0.287 to 0.341, indicating a more active quarter. The fund’s conviction in Information Technology stayed high, but it rotated within the sector, cutting NVDA while adding MU and SNDK.

This Quarter at a Glance