IBM Corp shares finally settled at $73 even, down $5, after its dreadful third quarter report, but by 10am Friday morning, 1m shares had been traded – an enormous number – and they were down at 71.875, and later went as low as $68.875: next flag point for the share price is $64 a share, which was the book value of the company at the end of June: if the share price falls below that, it in rather simplistic theory means investors would do better to break IBM up and sell the assets to the highest bidder than to continue to hold the shares.