Across the alert history, 22 sets have had stock movement worth calling: 151, Mega Evolution, Pitch Black, Destined Rivals, Ascended Heroes, Prismatic Evolutions, Black Bolt, White Flare, Perfect Order, Phantasmal Flames, Surging Sparks, Delta Reign, Journey Together, Stellar Crown, Temporal Forces, Twilight Masquerade and more. The heaviest alert volume right now sits on 151, Mega Evolution and Pitch Black.
That shifted over the following month. Between 10 October and 10 November, 30th Celebration products made up 527 of the 1,859 product pings across our UK Pokémon monitors, more than the next three sets combined: Pitch Black, Delta Reign and Destined Rivals.
Older sets do not automatically appreciate. Prismatic Evolutions has held because supply genuinely stopped; Pitch Black is the most heavily printed set of its era and has behaved accordingly. Treating "older" as "scarcer" is the most common way to lose money on sealed product.