You can save a broken streak by using your coins. The save is available only for the next 24 hours and before you make a prediction for the next day. The save can be used only once a week. The saved day adds up to your existing streak score and your streak continues. 

For example, if you get correct predictions on Sunday and Monday, get an incorrect one on Tuesday & save it, and get it right on Wednesday: your streak score will be 4.

You can not save your streak if the last prediction for a week is incorrect or missed.