It is absolutely not advisable to enter a market during or immediately after a bull run, it is better to wait for the market to decline and stabilize before buying into it, buying or investing at the very peak of a bull run is one of the most risky and foolish thing to do as an investor who have a enough knowledge and experience of what investment is all about.
So for me, it's a wait for correction before buying, if you buy at the peak of the bull run, you might end up waiting for years before you get another chance of selling at a profit.