Fidelity Japan 1996:

Here is an example of a fund that made a spike top. When a fund makes a spike top its NAV turns down ahead of momentum. This rarely happens to a very good trending (high momentum) fund. The Biotech funds were an exception to this in March of 2000.

Notice how its falling momentum and sell stop could have been used to avoid most of this correction despite the spike top. The same was true of the Biotechs in 2000.