Depends on how long you are willing to hold and at what time you buy.  If you plan to hold for a year or two before taking profits ... it's pretty safe.  If you plan for short term, you need to make sure you are buying the dip.  Right now, I believe we are near the bottom.  BTC could still drop down to the 4k to 6k range.  However, when you look at the big picture, it's around where it should be ... so are all the alts.