As far as Zynga stock owners and traders are concerned, it is by definition a surprise. If the loss had been expected then the price would have gone down earlie

As far as Zynga stock owners and traders are concerned, it is by definition a surprise. If the loss had been expected then the price would have gone down earlier. Alternatively, one could argue "hey, I knew that a large loss was possible, but consider that a large unexpected gain was also possible, so the price I paid last week as fair". In any case, the loss was not certain.