AssetMark Financial Holdings Inc. filed SEC Form 8-K: Termination of a Material Definitive Agreement, Completion of Acquisition or Disposition of Assets, Material Modification to Rights of Security Holders, Changes in Control of Registrant, Leadership Update, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Other Events, Financial Statements and Exhibits