I'm thinking that if PRB trades a little lower tomorrow and stays under .55 to .56 as a high that probabilties favor an important low. I would consider the .50 level as an important support level even if it sells below there temporarily.
.50, 5, 50, 500 and so on is the second most pivotal number for support and resistance with 1, 10, 100, 1000 and so on being the most powerful.