Odaily News Huidu posted on the Grayscale explains the S-3 form. Typically, an issuer will submit a registration statement for an initial public offering of equity securities registered under the Securities Act on Form S-1. However, GBTC is eligible to use Form S-3, a shorter document incorporated by reference into its SEC disclosures and reports, because its shares have been registered under the Securities Exchange Act of 1934 since January 2020, and meet other SEC requirements. Before GBTC can be converted into an ETF and shares issued in a registered manner under Form S-3, NYSE Arcas 19b-4 petition must be approved, a Regulation M exemption or other relief must be obtained, and the Form S-3 must be issued by SEC declares it effective.