Board Thread:General Discussion/@comment-27464043-20151230192612/@comment-28278649-20180219081844

The Collector will face Thanos and lose his Stone to him, Loki gives the Tesseract to him, the Mind Stone is nearly taken from Vision (hence why he's bruised behind Cap) but he still keeps it, and the Time Stone will be involved in the fight in NY.

This is all based on the trailers and BTS reports from the set.