That happened the last time they were added to an index although the pop didn't last. That's one of the interesting things about this stock. there are only 20 million or so shares outstanding, of which about half are owned by insiders or institutions. Add those owned by people like me who are holding for the long haul, and 1.5 million may cause a huge pop.
I was a little unclear by the announcement, is UPI definitely in, or are they finalists to get in?