** Ether hoarder ETHZilla's ETHZ.O shares rise 2.6% to $2.39 premarket
** Citadel CEO Kenneth Griffin revealed a 5.3% stake in ETHZ, according to a regulatory filing late Thursday
** Last month, billionaire Peter Thiel had also disclosed his stake in ETHZ
** ETHZ held 102,264 ether worth roughly $462 million as of Sept. 19
** As of last close, ETHZ stock up 28% YTD