That's the issue with trying to value such fast moving...

That's the issue with trying to value such fast moving companies. One minute they seem to be valued fairly well, then the next they're announcing a massive development and the valuation completely changes! That's why when I'm investing in small caps, I'll attempt to find them when they're cheap but won't try to worry about timing the top. A price that looks expensive today can very quickly look very cheap with a bit of news. So I will buy when they seem cheap and then hold so long as the company continues to grow and improve, even if I feel the price may be a bit detached from the current fundamentals.

Made the mistake of selling most of my quite large PME position a while back thinking the price had run too high relative to the fundamentals. I still think it's a bit expensive based on current fundamentals, but that company has continued to kick goals and so the share price has continued to rally higher and higher. If only I had focused on the company and not the share price I would have a much bigger boat today!

Buffet is a pretty good example of someone who uses this strategy. He will find great companies and hold them for many years and even decades, completely ignoring the share price and focusing on whether or not the company is growing and improving. His track record is evidence of the efficacy of this method...