DISK is trading at $30.50, up 3.04%, with no confirmed specific catalyst. - DISK is the Tema Memory ETF, reflecting exposure to memory-chip companies rather than a single operating company. - The supplied overnight alert attributes the after-hours rise to a chip-sector recovery, but reporting did not confirm a specific cause. - Broader reports describe recent rebounds across semiconductor and memory shares, but establish no fresh DISK-specific catalyst for October 21; no DISK-specific announcement was identified.