Play it close to the vest.
[Idiom] PLAY IT CLOSE TO THE VEST. - Secrets to Keeping Your Strategies Concealed
Keep plans or ideas secret.
To "play it close to the vest" means keeping your plans, thoughts, or finances private, not revealing them to others. If you imagine someone playing cards while holding them close to their chest (or vest), you get an idea of the guarded, cautious approach this idiom is advising.
Example Sentences
In negotiations, he always plays it close to the vest, never revealing his budget or limits.
In negotiations, he keeps his budget and limits very private.
She played it close to the vest, not giving any hints about the new strategy to her competitors.
She kept the new strategy a secret from her competitors.
During the poker game, he played it close to the vest, making it hard for others to guess his hand.
During the poker game, he kept his cards and strategies secret.