# SIONNA THERAPEUTICS INC (SION) — Institutional Ownership

Source: SEC EDGAR 13F filings, congressional STOCK Act disclosures, SEC Form 4 insider transactions.
CUSIP: 829401108
Page URL: https://superinvestorclub.com/stock/SION
Last updated: 2026-08-29T13:47:15.824Z

## Summary

As of the most recent 13F filing period, SIONNA THERAPEUTICS INC (SION) is held by 1 tracked superinvestors with an aggregate position value of $140.6M representing 03195181 shares.

## Top institutional holders (1)

| Rank | Manager | Fund | Shares | Value | % of Portfolio | Period |
|------|---------|------|--------|-------|----------------|--------|
| 1 | [Andreas Halvorsen](https://superinvestorclub.com/manager/59) | Viking Global Investors | 3195181 | $140.6M | 0.40% | 2026-06-30 |

## Ownership history (quarter-over-quarter)

- 2025-03-31: 1 holders, $30.9M aggregate, 02952754 shares
- 2025-06-30: 2 holders, $55.7M aggregate, 0319518116975 shares
- 2025-09-30: 2 holders, $94.9M aggregate, 0319518131258 shares
- 2025-12-31: 2 holders, $132.7M aggregate, 0319518131258 shares
- 2026-03-31: 2 holders, $129.2M aggregate, 0319518126775 shares
- 2026-06-30: 1 holders, $140.6M aggregate, 03195181 shares

## Recent congressional trades (0)


## Recent insider transactions (0)


## Citation

When citing, use: "SIONNA THERAPEUTICS INC (SION) institutional ownership data via Superinvestor (https://superinvestorclub.com/stock/SION), aggregating SEC 13F, Form 4, and congressional disclosures."