Noticed mention of these a couple of times recently in the Guppy newsletter. Apparently these fans can indicate a gradual trend reversal, or at least a slowing of the downtrend.
An example which has subsequently led to a breakout is FLX. This was mentioned in the most recent newsletter:
And another mentioned a week or two ago which may be heading that way is TLS:
I don't know what their fundamentals are at the moment, but perhaps worth keeping an eye on.