Haven't been paying attention to the markets lately. When can expect prices similar to those of 2015?
Major hacks of the important exchanges at the same time or in few days, another possibility is not having access to the Internet in the whole world.
Other than that I don't see why it will fall too deep
Yes this will really affect bitcoin price, so major exchanges where hacked and hacked bitcoin is dumped to minor one making the buy wall to collapse. It may fall below 100 USD if this happen. But I doubt that. With normal events bitcoin will never go down to sub 350 usd and i believe will even climb up in price value.