A very interesting chart. These are not the kind of trades that can happen daily, but there are few charts where such things can happen due to news/economy/ sector etc.
Why it happened is not important, the main issue is , how to play it?
When one drops very quickly for 3-5 bars, most likely it will get a bounce of about 50%. Entry is key here. You have to let it consolidate (base formation) then jump in full position with v tight stop and exit at 1st weakness.