For International Business Machines (NYSE:IBM), the dominant piece of news in 2015 was the continuing deterioration of revenue. Following the third quarter, IBM had reported 14 quarters of revenue declines in a row, and while progress is being made in some areas, turning around a company as large as IBM takes a lot of time. Year to date, IBM stock is down about 14%.

IBM Chart

IBM data by YCharts.

With 2015 coming to a close, here's a look at some of the worst IBM headlines of the year.

Jan 12: Analyst estimate cuts
Starting off the year with a whimper, three companies cut their 2015 estimates for IBM in January. Jefferies, Deutsche, and Stifel all slashed revenue and earnings estimates, with the lowest EPS estimate being $15.17. Late in 2014, IBM abandoned its previous goal of hitting $20 per share in non-GAAP earnings in 2015.

March 7: Losing server market share
IDC released data related to the server market during the fourth quarter of 2014 in March, and IBM lost some major ground. The company's market share fell to 13.7%, down from 26.8% during the same period last year.

A big part of this decline was due to IBM's sale of its x86 server business to Lenovo, but that doesn't explain all of it. Lenovo gained about $975 million in server revenue year over year, but IBM lost nearly twice that. IBM's Power servers continue to struggle against x86-based systems, and while IBM is taking steps to correct this with the OpenPOWER foundation, progress has been slow.

April 20: Revenue slumps 12.9%
IBM reported its 12 quarterly revenue decline in a row in April, with sales slumping by 12.9% year over year. The good news is that sales were flat if divested businesses and currency effects are backed out. The bad news is that the headline numbers appear abysmal.

July 20: Revenue slumps again
IBM made it 13 quarters of consecutive revenue declines in July, reporting a 13.5% year-over-year decline in revenue during the second quarter. Revenue fell in every segment, and gross margins deteriorated in IBM's services and software segments. On an adjusted basis, revenue fell by just 1%, but there was enough disappointment to send shares tumbling.

Oct 19: A guidance cut
IBM reported a 14% year-over-year decline in revenue during the third quarter, but the real news was that the company slashed its EPS guidance for the full year. IBM announced that it expected non-GAAP EPS to be between $14.75 and $15.75, down from previous guidance of $15.75-$16.75.

The stock fell to its lowest level since 2010 following the guidance cut and subsequent analyst downgrades. Stifel analyst David Grossman slashed his price target to $160 per share, and Bernstein analyst Toni Saccanoghi knocked his price target down to $140 per share. Saccanoghi expects EPS to drop further in 2016.

Oct 27: SEC revenue recognition investigation
It's never good news when the SEC announces an investigation. In October, IBM announced that the SEC was conducting an investigation related to the accounting treatment of certain transactions. Last year, the SEC launched a separate investigation into IBM's cloud computing revenue recognition, eventually concluding that IBM had done nothing wrong.

Nov 19: Layoffs in Germany
IBM has been reducing its workforce aggressively in recent years as it transitions its business. At the end of 2014, IBM had a global headcount of about 380 thousand, down from about 430 thousand at the end of 2013. In November, it was reported that IBM was considering laying off 18% of its local workforce in Germany, amounting to about three thousand positions. This would represent less than 1% of IBM's global workforce, but it would continue the trend of trimming the global headcount.

Timothy Green owns shares of International Business Machines. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.