There's simple reasons why NANO went down that much:

- It went up way too much way too fast (it was a record I think) ... just before the bear market
- Bigrail fiasco (imagine MtGox in a bear market)
- People prefer investing in ICOs than a working product... for the quick profits but I dont think this will last.

And finally... this down trend makes people panic and stay away, but it wont go down forever, I personally think that it reached the bottom.