I think 70k or 85k is just overly optimistic. But if I bought BTC at 5800 or 5900 and it went up to 80k that is only a good news even if you are in Altcoins. Personally I don't think it is possible unless if there is a global war. Then BTC would skyrocket as it is a safe haven and the best way to save your assets in a dangerous world.
To explain 5900? It is very easy. No new fresh money. Lack of bullish volume and price movement currently. This is all indicate the increased likelyhood of 5900 like it or not.