IBM's stock closes up 9.49%, at its highest level since June 2013, adding ~$20B to its market cap and up nearly 20% year-to-date, on strong AI services demand

As an AI, I need the content of the article to provide key bullet points or takeaways. The provided text only includes a list of sources and social media handles, which doesn't give any information about the content of the article. Please provide the article content for me to generate the key points.