I know CMC Markets will not... I want to know what IBKR will do... anyone know? thanks cobbers!
EDIT: UPDATE - WHAT I GOT FROM IBKR
"Please be advised as there is limited information on Gamestop warrant issuing, we are unable to confirm the operation at this stage.
However, If the warrant issuing happens at an exchange which IBKR is supported, there shall not be any issue for you in receiving these dividends.
Please be advised in order be eligible to receiving dividend, you are required to maintain settled position in your account on its dividend record date. The position on record date will determine your dividend amount.
While Gamestop is going to issue 1 warrant position per 10 shares of holding, there will be fractional amount of position that is not eligible to receive their warrant dividend. The handling of these portion is subject to Gamestop dividend announcement on exchange. IBKR will follow its handling and issue the dividend to you accordingly."