It is generally very dangerous to short during a bull run, but in this case I think there are significant reasons to expect a pullback as I have shown on the chart. Based on past performance, I would expect it to drop into the lower target from $4500 - $4700. Alternatives to shorting Bitcoin would be to buy altcoins that have proven to perform particularly well during Bitcoin's pullbacks. I have already posted charts on a few that I still think are valid. Two of those are ZEC and XMR. Both have very strong USD trends(especially XMR) and are at very interesting points in their market cycles that make them very attractive. Another two are BTS and XLM. These are more of wildcards. I'll link my charts below.
Having a strategy on how to manage your portfolio based on Bitcoin's larger moves is extremely valuable. It is something that I have struggled with in the past and it is not altogether an easy situation to navigate. I recommend stacking your portfolio with coins that are increasing in value against USD and are also holding strong or increasing against Bitcoin during these times.
Where Bitcoin will move after this is a mystery to me. My gut says it should go down, but it is the most bullish currency/asset in the world so who knows. You could argue that it would be more healthy than not for Bitcoin to enter a bear trend so that it can refuel and begin to move gain in a year or two. This would also support any theories about the economy entering a recession over the next couple of years, which I think is probable and in the case of a bailout down the line, obviously that would be good news for Bitcoin. But this is all just hypothetical and speculative.