Atmos Energy (ATO) adjusts commission terms on $1.7B stock offering

Rhea-AI Filing Summary

Atmos Energy Corporation has an existing common stock offering with an aggregate offering price of up to $1,700,000,000. This supplement updates how commissions are described in its forward sale agreements tied to that offering.

For each forward sale agreement, the forward seller will receive a commission, reflected as a reduced initial forward sale price, at a mutually agreed rate that will not exceed 2.50% of the volume-weighted average sales price of borrowed shares sold during the applicable period. No other changes to the prior prospectus supplement are made.

Filed Pursuant to Rule 424(b)(3)

Registration Statement No. 333-283563

SUPPLEMENT NO. 1 dated February 4, 2026 to the

PROSPECTUS SUPPLEMENT dated December 3, 2024 to the

PROSPECTUS dated December 3, 2024

Atmos Energy Corporation

Common stock

Having an Aggregate Offering Price of up to $1,700,000,000

The third sentence of the fourth paragraph on the cover page of the Prospectus Supplement is replaced in its entirety with the following:

“In connection with each forward sale agreement, the relevant forward seller will receive, reflected in a reduced initial forward sale price payable by the relevant forward purchaser under its forward sale agreement, a commission at a mutually agreed rate that will not exceed 2.50% of the volume weighted average of the sales prices of all borrowed shares of our common stock sold during the applicable period by it as a forward seller.”

The first sentence of the third paragraph under the heading “Plan of Distribution (Conflicts of Interest)—Sales Through Forward Sellers” on page S-18 is replaced in its entirety with the following:

“In connection with each forward sale agreement, we will pay the relevant forward seller, in the form of a reduced initial forward sale price payable by the relevant forward purchaser under the related forward sale agreement, commissions at a mutually agreed rate that will not exceed 2.50% of the volume weighted average of the sales prices of all borrowed shares of common stock sold during the applicable forward hedge selling period by it as a forward seller.”

Except as expressly set forth herein, no other changes to the Prospectus Supplement are being made by this Supplement.

FAQ

What total amount of Atmos Energy (ATO) common stock is covered by this offering?

The offering covers Atmos Energy common stock with an aggregate offering price of up to $1,700,000,000. This figure reflects the maximum value of shares that may be sold under the existing prospectus and related prospectus supplement, as updated by this new supplement.

What commission rate will forward sellers receive in Atmos Energy (ATO) forward sale agreements?

Forward sellers will receive commissions at a mutually agreed rate that will not exceed 2.50% of the volume weighted average of the sales prices of all borrowed shares of Atmos Energy common stock sold during the applicable forward hedge selling period under each forward sale agreement.

How are forward seller commissions paid in the Atmos Energy (ATO) offering?

Commissions are effectively paid through a reduced initial forward sale price owed by the forward purchaser. The agreed commission, capped at 2.50% of the volume weighted average sales prices of borrowed shares, is embedded in this reduced price under each forward sale agreement.

Which parts of the Atmos Energy (ATO) prospectus supplement are changed by this new supplement?

This supplement replaces one sentence on the cover page and one sentence in the “Plan of Distribution—Sales Through Forward Sellers” section. Both revised sentences clarify how forward seller commissions, capped at 2.50%, are calculated and paid. No other sections are changed.

Does this Atmos Energy (ATO) supplement change anything besides forward seller commission language?

The supplement states that, except for the expressly updated sentences about forward seller commissions and their calculation, no other changes are made. All remaining terms and disclosures in the prior prospectus and prospectus supplement continue to apply without modification.