Volume "Spikes" at the close Friday?

[Lyehopper]

If this was discussed here this weekend I missed it....

Who noticed the volume "spikes" on numerous stocks Friday right at the close? Who saw this happen on stocks you watch, AND.... Who has an explanation?.... I've seen this happen before but I've never been able to figure out exactly what the deal is.... Here's an example....

[jiesen]

yeah, I noticed it too with AMLN. They're probably just large pre-arranged trades for index rebalancing, or some big institutions shifting their positions around.

[Rob]

Window Dressing

[Gatorman]

Window Dressing

Rob:
I have always liked terse responses but I need a bit more explanation. Care to elaborate?

[IIC]

Yeah...happened w/ my last contest pick...MOVE...I sold it at 5.28 at 3:59...then it goes dn to about 5.10...then on the last trade of about 2mil shs it jumps to 5.48...IIC

[Rob]

Window Dressing

Rob:
I have always liked terse responses but I need a bit more explanation. Care to elaborate?

Gator, I don't guess I could explain it any better than this page at Motley Fool.