There have been multiple top extensions in US equity indices, including signals from the three major measures - the S&P, Dow and Nasdaq. This last example came two days ago from the popular QQQ instrument:
This is a warning that the present rally is now over-stretched and that you should lighten up long positions or at least take some protection against a drop. The longer-term outlook remains bullish as prices have moved up from weekly-scale compressions but some consolidation or dip is now likely. There may be chances to catch any forthcoming drop with short sales but these must be considered tactical only and quick profits should be taken. Europe probably provides better short-sale opportunities than the US for the simple reason that the markets here have been trading sideways to downward for some considerable time, reflecting the poorer fundamentals. There have been no 'topping' signals in Europe but there are plenty in the US, so we assume that all markets will now pause in their rise. The usual caveats apply to top extensions - these mark the end of a rise and not necessarily the start of a decline. Market tops (even short-term ones) form as a process rather than as a single event, unlike bottoms which are often sudden and singular.
We will watch and advise if we see any particularly good short-sale candidates, but lacking that please sell carefully - not on dips but on rallies.