NVidia probably liked the high prices (because of miner demand), produced accordingly and kept the price stable. These high prices probably ensure a nice profit margin for a longer time then normal during this stage of the product's life cycle. However a side effect might be somewhat slower sales then they planned (for example because miners will buy anyway but gamers are waiting for the nextgen cards). That means they're left with a lot of stock, which sells, but not at their normal rate. NVidia normally has a very predictable product life cycle but I think they are now in something that is (to them) uncharted territory.

This could lead to stuff like their accountants saying: "You've got an awful lot of stock which isn't selling as fast as you thought. We think that's a risk". Which might compel them to set money aside for stock risks.