Unemotional

He's dry and unemotional.

Tom is unemotional.

You're unemotional.

Callous, unemotional children can sometimes become adult sociopaths.

Tom is unemotional, isn't he?

There is something tropical and exotic about her which forms a singular contrast to her cool and unemotional brother.

His aversion to women and his disinclination to form new friendships were both typical of his unemotional character.

Mary is unemotional, isn't she?

Think of me as an unemotional woman.

an unemotional person

On a side note, I would like to also point out that when Mike was asked about what to do about a losing position, he replied that the trader must analyze the situation and make an unemotional decision.