FTSE100 modestly lower, with the miners a major millstone

Any reason for POLY taking a caning other than market sentiment? The RNS out today didn't seem to be a negative one. That they are probably going to drop out of the Ftse may have a little bearing but didn't think it would impact that much. trying to decide whether to top up or am i catching a falling knife.[Rhetorical question]

GL

Alex

FTSE 100 slightly lower as weak miners hamper progress