Have you all notice that on Friday's the pps seems

Have you all notice that on Friday's the pps seems to jump up at end of trading, then on following Monday it goes back down. Is that because some don't want to go into weekend without shares in case of news release? Or is it MM's closing out the end of week trades? Just curious as this seems to be a long standing pattern I notice since I began tracking closing price of NTEK and NTGL.