The U.S. Amazon site has some "popular best sellers on Kindle" on sale. This is for today only. Some of these don't interest me at all, but there were only six of them so I went ahead and listed them all since I know my followers enjoy a large variety of books.
Red Rising is $1.99 and The 5th Wave is $2.99. The other four are $4.99, so it's not a huge sale.
I did snag Red Rising because I've seen several positive reviews for that series lately and it was already on my radar. $2 is a difficult price point to ignore if I'm already interested! I might have grabbed The Martian at $2, but I'm not in any hurry to read it so $5 didn't tempt me.