The AI frenzy and a quantum computing development helped IBM stock recover.A tailwind from the artificial intelligence (AI) boom, along with an apparent breakthrough in quantum computing, helped push IBM (IBM 0.65%) stock back to near-record levels in September. IBM stock gained 15.9% last month, according to data provided by S&P Global Market Intelligence, largely erasing the losses suffered over the summer. AI and quantum computingIBM's AI business doesn't generate a lot of headlines, but the company has ...