No need to ask why it's happening to Waves. The market is in bad shape for this week so majority of the coins are dropping low.
And for few days bitcoin dropped more than $1,000 so it gives effect to the market as whole. If you see your losses, you have to hold until now so you can recover later on.
But if you can't wait for the recovery, cut your losses.
Cut loss is not always right but also not always wrong. Its relatives. However we can choose it based on our situation. Do it if you think its beter for you. I agree that not only waves that goes down but most of crypto is not in good shape. I am not happy with this and also the other but this is the way of crypto moves.