An alternative take: maybe we're only seeing the price of sub-ledger bitcoin (as held on exchanges) decrease during bitcoin's "bank runs." It's hard to wrap my arms around that, but I could see that being true.
Interesting idea -- separates the pricing mechanism btwn on-exchange and off-exchange btc, like they're two distinct type of conceptual entities. Not sure what implications that has, but I'm going to noodle on it.