Market Crash
A market crash in FIFA refers to a sudden drop of Item prices (especially Player prices) in the Transfer Market.
Causes
Usually, discounted pack offers & promotions from EA cause a market crash. As more people do buy packs during a pack promotion, there will be more chances to get Inform players from the packs, especially from rare players packs and list them on the Market, so this will trigger a crash on the Market and will cause the price ranges to go down.