Why do some exchanges have Wallets down when others don't?

[paramind22]

A good exchange has had three odd coins with high price gains have their wallets down.  I checked another exchange I'm on and the wallet isn't down for this one coin.  It's kind of aggravating because it looks like corruption.  One exchange is big, the other with the up wallet is much smaller.  Is this just someone on the inside who isn't managing well, or maybe someone taking a cut where they shouldn't be?