I admit that I might be wrong, but with just 21,000,000 Bitcoins in existence partnered with an increasing money supply, it's hard not to see SIX DIGITS.
It was the main point that allowed the price of bitcoin to increase many times what it was before. ATH higher than $200k can be expected, but in the end it really depends on how the money flows into the market. If large investors start to find safe ways to buy bitcoins then obviously the high demand for the coin will increase its value automatically. We are on the road to reach a new ATH, but we don't know when that will happen and how high the realization will be.
I'm optimistic about the price of bitcoin in the long term, but it probably won't be that easy to reach $500k. It would take a lot of support and large amounts of money to drive bitcoin's price higher than $200k, but the most realistic thing right now is to set up a stronger portfolio to expect future returns.