  In a unified framework we study equilibrium in the presence of an insider
having information on the signal of the firm value, which is naturally
connected to the fundamental price of the firm related asset. The fundamental
value itself is announced at a future random (stopping) time. We consider two
cases. First when the release time of information is known to the insider and
then when it is unknown also to her. Allowing for very general dynamics, we
study the structure of the insider's optimal strategies in equilibrium and we
discuss market efficiency. In particular, we show that in the case the insider
knows the information release time, the market is fully efficient. In the case
the insider does not know this random time, we see that there is an equilibrium
with no full efficiency, but where the sensitivity of prices is decreasing in
time according with the probability that the announcement time is greater than
the current time. In other words, the prices become more and more stable as the
announcement approaches.
