Don't afraid people stealing your ideas

I attended a lot of tech events for networking and sharing in the past year.
During the conversation with some startups, I realize that normally they are not willing to share all the problem or situation they are facing.
After asking more only know that they afraid people will steal their ideas, so everything only mention a little bit.
Of course, I can't deny the possibility of your ideas being stolen.
But please understand that, what is the consideration between after people listened and start taking action.

1. Development cost & risk

This is the most common issue. You afraid people will start developing after heard your ideas, then you already lost the first mover advantage. But, you are totally ignoring the cost & risk of the ideas development.

Basically, you think how perfect, unique, profitable this idea is (believe me, normally it is based on your own assumption only). People will consider their own resources, cost of development, cost of A&P, and the risk before start doing it. This is the reason why people won't start development immediately after they heard an idea.

2. The personal experience of the idea creator

If both investment firm general manager and your neighbour recommend you two companies share, who will you listen to?
If you and your team are first time entrepreneurs, I think you can share your ideas. No one will care about it. If you still got some consideration, then find a trustful person and share with him/her privately. So you can get feedback of your idea and improve it.

3. The company behind this guy got huge fund, they may execute it very quickly
Yes, but think in the positive way: They already have so much money, why they want to jump into a unknown market? With their resources, fund, connection, they can easy do other proven business.

Hope it can help, cheers!