$5k this year is easily doable because we saw how much litecoin price went up after segwit and bitcoin only needs a doubling over the next 4 months to reach $5k.
Whether it really happens though will depend on how much drama is created during the planned hard fork later this year.
For Litecoin, it was easier. The LTC market cap was only around $100 million in March, and it increased by around $900 million to reach the $1 billion mark. But the case with Bitcoin is different. It needs an increase of $40 billion to double its market cap.