I want to know if this card will go up and down

Pricing is expected to go UP.

Why the Oracle sees it this way

Lion Market sees a classic post-rally cooldown. While a PSA 10 copy managed to secure a massive $44,699 sale in July, that isolated peak contrasts sharply with the rest of the card's exact-tier history, which sits closer to a $25,300 median over the last six months. Because exact-tier history is limited at the top, we have to look at the highly active lower grades to see where demand is actually heading. Across the broader market, buyers are stepping back. PSA 8 copies, which are very easy to trade, have seen their 30-day median drop to $2,431 from a 90-day median of $2,693. PSA 7 and PSA 6 copies are showing similar slight declines. Modern counterparts confirm this cooling trend; the 2017 Japanese Shining Legends Shining Mew saw its PSA 9 tumble from $365 in May to $227 in June. Chase cards that spiked in the spring are universally catching their breath. When highly liquid lower grades start to soften after a massive spike, the illiquid premium tiers usually follow suit. The sparse observations for PSA 10s mean there is high uncertainty, but the robust evidence from the rest of the CoroCoro Mew population strongly suggests the ceiling has been reached. Buyers are no longer willing to pay peak prices, making a near-term dip the most likely scenario as price discovery pulls the top tier back down to earth.