Volume Spike Investor

There has been a pick up in trading activity of general Motors Corp. (NYSE: GM) this afternoon via the put and call and options.
The JULY08 $15.00 CALL and $15.00 PUT strikes have seen a sudden pick up:
$15.00 CALLS saw    14,095 contracts trade and the open interest was 28,681 before today.
$15.00 PUTS saw 14,162 contracts trade [...]