Well I bought in at 16.10 and just sold at 13.00 after mtgox kept going down, now the price is very unstable got to 12.50 now it's at 13.00
You only lose money trading if you sell lower than you buy. The only exception to this is if a company goes bankrupt or the price never recovers. This goes for any market.
If the price drops below what you bought it for, just WAIT.
yea if the price drops I normally buy some more depending on how much of a risk. that way it it has to go up less to make yourself come out even.
anyway 12.40 is around my magic number.