Perhaps this is a biased forum for this question, but I've never figured this out. At what stage is it safe to share mathematical ideas? Many have told me that there is serious danger of ideas being stolen if shared in a premature form, but I've found that sharing ideas often moves things along much more quickly than holding them back.

This is definitely not the best question for MO, but I think some expert advice on the topic may be helpful to young mathematicians.