Core terms
S-1
A Securities Act registration statement commonly used by issuers that cannot use a shorter form. It may register newly issued securities, resale by existing holders, or both.
Calculation framework
Primary offering potential shares ≈ registered primary dollar amount ÷ assumed offer priceResale-only registration: new shares created at registration = 0; trace the underlying issuance separatelyWhat traders should verify
Separate primary from resale securities, then follow amendments, EFFECT, the final prospectus, closing disclosures, and later shares-outstanding updates.
Do not conflate
Filed does not mean effective; effective does not mean issued; registered does not mean sold.