The stock immediately dropped in after-hours trading yesterday following the announcement, but it's continued to head lower all day long today.
Right now, shares are down 8.0%, trading around $190.60.
IBM is one of the 30 stocks that comprises the Dow Jones Industrial Average, and it's dragging the index lower.
The Dow is now trading around 14,500 after hitting a high near 14,540 earlier this morning, and is down 0.2% on the day.
Below is a chart of IBM stock. The tinted section in the middle shows the after-hours session yesterday.