Stay informed —— คอยตามติดข่าวตลอด คอยเงี่ยหูฟังข่าว อย่าได้ตกข่าว

To keep abreast of = to remain up to date with; informed; aware; up-to-date
                                    Ex: We'll keep you abreast of recent developments.

To keep sb posted =  to make sure that someone always knows what is happening
                                    Ex: Keep me posted on anything that happens while I'm away.

To keep someone in the loop ....https://www.youtube.com/watch?v=5cQv8pWsnEE
ลองคลิกไปดูที่เว็บไซต์นี้ โดยเฉพาะ  expression # 6 & #7