Market Makers and Specialists are always hiding their trading activities. College and Graduate School did not teach this course. Put yourself in their shoes, then maybe you can get answer. Do homework is important.
Could I get you to explain further?
The Nasdaq site shows 1.1 million total shares trading after hours. The bump after the market closed was around 60 million shares. My best guess was a large block transfer to close a short position. But I don't understand how it could execute without reporting on Nasdaq site or showing as a volume spike at end of day??? Btw, wsj quotes show day trade volume only and the extra 60 million was reported as of normal market close.
It looked like a pre-arranged trade between institutions. Possibly (likely?) an Intel buyback of a large block.
U.S. exchange after-hour markets The NYSE and ASE provide crossing sessions in which matching buy and sell orders can be executed at 5:00 p.m. based on the exchanges' 4:00 p.m. closing prices. The BSE and PSE have post-primary sessions that operate from 4:00 to 4:15. CHX and PCX operate their post-primary sessions until 4:30 p.m. Additionally CHX has an "E-Session" to handle limit orders from 4:30 to 6:30p.m.