No AI bubble yet, economist warns—watch for a 2026 IPO surge as OpenAI looms

Fortune reports that top economist Owen Lamont says the AI or AI-adjacent stock run isn’t a bubble yet, because the four ‘horsemen’ of a bubble — overvaluation, bubble beliefs, inflows, and issuance — haven’t all aligned. Valuations and frothy sentiment exist, but there’s a surprising lack of IPOs, which Lamont views as the key trigger. A potential mega-cycle could arrive in 2026 if high-profile private firms like SpaceX go public and OpenAI plans an IPO, signaling the era of abundant offerings and possible bubble risk if insiders start selling. The piece contrasts current spending on AI with past bubbles and notes that the market remains expensive but not at dot-com extremes.