Free Writing Prospectus (Form FWP)

Filed Pursuant to Rule 433

Registration No. 333-292646

Issuer Free Writing Prospectus, dated June 3, 2026

PRICING TERM SHEET

June 3, 2026

Celcuity Inc.

$500.0 Million Aggregate Principal Amount of 0.250% Convertible Senior Notes due 2032

The information in this pricing term sheet supplements Celcuity Inc.'s ("Celcuity") preliminary prospectus supplement, dated June 3, 2026, (the "Preliminary Prospectus Supplement"), filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the "Securities Act"), relating to an offering of convertible senior notes (the "Convertible Notes Offering"), and the accompanying prospectus, dated January 9, 2026. This pricing term sheet supersedes the information in the Preliminary Prospectus Supplement to the extent inconsistent with the information in the Preliminary Prospectus Supplement. Terms used, but not defined, in this pricing term sheet have the respective meanings set forth in the Preliminary Prospectus Supplement. As used in this pricing term sheet, "we," "our" and "us" refer to Celcuity. Celcuity has increased the size of the Convertible Notes Offering from $400,000,000 to $500,000,000 (or, if the underwriters of the Convertible Notes Offering fully exercise their over-allotment option, $575,000,000). The final prospectus supplement relating to the Convertible Notes Offering will reflect conforming changes relating to such increase in the size of the Convertible Notes Offering.

Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change

If a make-whole fundamental change occurs and the conversion date for the conversion of a Note occurs during the related make-whole fundamental change conversion period, then, subject to the provisions described in the Preliminary Prospectus Supplement under the caption "Description of Notes-Conversion Rights-Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change," the conversion rate applicable to such conversion will be increased by a number of shares of Common Stock (the "Additional Shares") set forth in the table below corresponding (after interpolation as described below) to the make-whole fundamental change effective date and the stock price of such make-whole fundamental change:

If such make-whole fundamental change effective date or stock price is not set forth in the table above, then:

Notwithstanding anything to the contrary, in no event will the conversion rate be increased to an amount that exceeds 11.2422 shares of our Common Stock per $1,000 principal amount of notes, which amount is subject to adjustment in the same manner as, and at the same time and for the same events for which, the conversion rate is required to be adjusted pursuant to the provisions described in the Preliminary Prospectus Supplement under the caption "Description of Notes-Conversion Rights-Conversion Rate Adjustments-Generally."

We have filed a registration statement (including a prospectus) and the Preliminary Prospectus Supplement with the SEC for the offering to which this communication relates. Before you invest, you should read the Preliminary Prospectus Supplement and the prospectus in that registration statement and other documents we have filed with the SEC for more complete information about us and this offering. You may get these documents free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, we, any underwriter or any dealer participating in the offering will arrange to send you the Preliminary Prospectus Supplement (or, when available, the applicable final prospectus supplement) and the accompanying prospectus upon request to: Jefferies LLC, Attn: Equity Syndicate Prospectus Department, 520 Madison Avenue, New York, NY 10022, by telephone at (877) 821-7388 or by email at [email protected]; J.P. Morgan Securities LLC, Attention Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, or by email at [email protected] and [email protected]; TD Securities (USA) LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or by email at [email protected]; and Guggenheim Securities, LLC, Attention: Equity Syndicate Department, 330 Madison Avenue, New York, NY 10017, by telephone at (212) 518-9544 or by email at [email protected].

The information in this pricing term sheet is not a complete description of the Notes or the Convertible Notes Offering. You should rely only on the information contained or incorporated by reference in the Preliminary Prospectus Supplement and the accompanying prospectus, as supplemented by this pricing term sheet, in making an investment decision with respect to the Notes.

ANY DISCLAIMERS OR OTHER NOTICES THAT MAY APPEAR BELOW ARE NOT APPLICABLE TO THIS COMMUNICATION AND SHOULD BE DISREGARDED. SUCH DISCLAIMERS OR OTHER NOTICES WERE AUTOMATICALLY GENERATED AS A RESULT OF THIS COMMUNICATION BEING SENT VIA BLOOMBERG OR ANOTHER EMAIL SYSTEM.