---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-120808"
form_type: "8-K"
ticker: "LNT"
cik: "0000352541"
company_name: "ALLIANT ENERGY CORP"
filed_at: "2025-05-15T23:59:59+00:00"
generated_at: "2026-05-21T06:21:02.435467+00:00"
event_type: "debt"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Alliant Energy closes $575M 3.250% convertible notes offering due 2028

## Summary
- $575M aggregate principal of 3.250% convertible senior notes due 2028 issued, including full $75M option exercise.
- Initial conversion rate 13.1773 shares per $1,000 principal, conversion price ~$75.89/share (27.5% premium).
- Net proceeds ~$567M (after discounts) to repay debt, reduce commercial paper, or general corporate purposes.
- Notes mature May 30, 2028; interest payable semi-annually starting Nov 30, 2025.

## SEC filing metadata
- accession: 0001193125-25-120808
- form_type: 8-K
- ticker: LNT
- cik: 0000352541
- company_name: ALLIANT ENERGY CORP
- filed_at: 2025-05-15T23:59:59+00:00
- event_type: debt
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 1.01, 2.03, 3.02, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/352541/000119312525120808/0001193125-25-120808-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/352541/000119312525120808/d928152d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-120808
- JSON: https://secwatch.observer/filing/0001193125-25-120808.json
- Plain text: https://secwatch.observer/filing/0001193125-25-120808.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.