2026-Q1 Swiss National Bank 13F Filing: SNB opens new AZN stake worth $1.20B

Every quarter, any institutional investment manager that exercises discretion over $100 million or more in U.S. equity assets must file a Form 13F with the SEC, disclosing its U.S.-listed stock holdings. This walkthrough uses the Swiss National Bank's 2026-Q1 filing as a live example to teach you how to read one.

1. What a 13F actually discloses. The form is a point-in-time snapshot of U.S.-listed equity positions: ticker, share count, and market value on the reporting date, and nothing else — no trade rationale, no forward plans, no cash, no non-U.S.-listed securities. In this filing, the Swiss National Bank reported 2301 positions as of 2026-03-31, compared with 2311 in the prior quarter, with a turnover ratio of 0.140197 — a reminder that only a small slice of the book actually changed hands during the quarter.

2. How to spot a genuinely new position. When a holding carries a new_buy action and no prior-quarter value, it is a brand-new stake rather than an add to an existing one. AZN is the standout here: a fresh position worth $1.20B, equal to 0.69% of the portfolio. SUNB is a smaller new buy at $104.4M. Contrast that with XOM, which already existed in the prior quarter and was simply increased.

3. How to read an add versus a trim or a full exit. An add means the manager bought more shares — a real, active decision. A trim would mean selling part of a position; sold_out would mean exiting it entirely. In this filing's top changes there are no trims and no exits: every active move is an add or a new buy. XOM is the clearest example of an add: the position grew by +$693.9M to $2.10B, and its portfolio weight rose from 0.84% to 1.21%.

4. The counterintuitive case: an add with a falling dollar value. Several adds in this filing show a negative value change even though shares were bought. MSFT's change was -$1.69B, AAPL's was -$108.5M, and AMZN's was -$190.4M — all with the action add. The filing's own note explains the direction: 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. So a negative dollar delta next to an add is not a sell signal.

5. What an unchanged holding would tell you — and why turnover matters here. None of the top changes in this filing is unchanged; every listed line is an active decision. But with 2301 reported positions and a turnover ratio of 0.140197, the overwhelming majority of positions did not change hands this quarter. For a position that is unchanged, any value or weight movement is pure price drift — the manager neither bought nor sold a single share.

6. What the overall pattern shows about this quarter's strategy. The active decisions were entirely accumulative: no trims, no exits, two new buys, and adds spread across health care, energy, and technology. The bank added to AAPL and MSFT, the two largest values in this top-changes list, yet both recorded negative value changes. Meanwhile the HHI fell from 0.019134 to 0.016841 and the information technology weight dropped from 0.3606 to 0.3386. In short: the trades were mostly buys, but prices — especially in tech — moved the other way.

A quick note on the table below: rows marked 'shares added; price fell' are adds whose dollar value declined. The filing's own wording is that 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.

This Quarter at a Glance