Panicked for awhile initially...what else could one do.
But what kept me from total destruction was not having more invested than i could afford to lose, there is not get rich quick in this game.
Always kept in mind that nothings guaranteed - its an educated "gamble" on a number of companies after all.
So that allowed me to look the other way and just hope it turned around at some point. When it did start turning around increased by investments significantly, again only with what i was willing to lose if it went sour.
with these things its your mind that is your worst enemy --> have to train your mind to remain objective.
I like [MENTION=97943]SauRoNZA[/MENTION]'s mention of objectivity - I need that because I've knee-jerk reactions I need to watch out for but I was wondering how many people saw it as an opportunity and how many people were worried their investments would never recover (that charming warning: Past performance is not a guide to future performance, nor a reliable indicator of future results or performance is kind of intimidating.)
My stock/options grants plummeted, but I hade enough cash to put down a deposit on a flat, so I bought one then (“buy at the bottom”/“when there’s blood on the streets” strategy). It was a great investment, and the stock grant price bounced back and far exceeded the original price anyway (took many years though).