SOUTHEASTERN ASSET MANAGEMENT INC/TN/: REGENERON PHARMACEUTICALS (REGN): Quarterly 13F Position History
As of Q1 2026, SOUTHEASTERN ASSET MANAGEMENT INC/TN/ reported 130,662 shares of REGENERON PHARMACEUTICALS (REGN), worth $101.0M and representing 5.0% of its 13F equity book. Quarter-over-quarter share count change: 35,130 (-21.2%) . The position first appeared in Q1 2025 and has been disclosed across 5 13F-HR filings in Pactolio's tracked window.
- 130,662Shares Held (Latest Filing)
- $101.0MReported Market Value (Latest Filing)
- 5.0%Portfolio Weight (% of 13F Equity Book)
- 35,130Quarter-over-Quarter Share Change
- -$27.0MQuarter-over-Quarter Value Change
- 165,792Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 5 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 130,662 | 35,130 | -21.2% | $101.0M | 5.0% | $772.6 |
| Q4 2025 | 165,792 | +21,185 | +14.7% | $128.0M | 5.7% | $771.9 |
| Q3 2025 | 144,607 | 15,974 | -9.9% | $81.3M | 4.2% | $562.3 |
| Q2 2025 | 160,581 | +45,701 | +39.8% | $84.3M | 4.3% | $525.0 |
| Q1 2025 | 114,880 | — | — | $72.9M | 3.9% | $634.2 |
Methodology & FAQ
How This Position History Is Sourced
Each row is one SEC Form 13F-HR filing disclosing this position. Share count, market value, and reported quarter are taken verbatim from the filing; portfolio weight is recomputed against the same filing's total reported equity book. Implied price-per-share is market value divided by shares — a quarter-end mark, not the manager's cost basis. See the full methodology document for the normalization rules.
When did SOUTHEASTERN ASSET MANAGEMENT INC/TN/ first disclose a REGN position in 13F-HR filings?
SOUTHEASTERN ASSET MANAGEMENT INC/TN/ first reported REGENERON PHARMACEUTICALS (REGN) on its 13F-HR filing for the period ending 2025-03-31 (Q1 2025). The position has appeared on 5 reported quarters within Pactolio's tracked window.
What was SOUTHEASTERN ASSET MANAGEMENT INC/TN/'s most recent quarter-over-quarter share-count change in REGN?
Between Q4 2025 and Q1 2026, SOUTHEASTERN ASSET MANAGEMENT INC/TN/ reduced its REGN position by 35,130 shares (-21.2%), leaving 130,662 shares at a market value of $101.0M.
Does the implied price-per-share represent SOUTHEASTERN ASSET MANAGEMENT INC/TN/'s cost basis in REGN?
No. The implied price-per-share column is the 13F-HR reported market value divided by reported share count on the filing date (end of quarter). It is a quarter-end mark, not a cost basis or transaction price. Use it as a sanity check on the value column, not as an indicator of the manager's entry or exit price.