The AI stock is trading down while the rest of the sector is soaring.Back in late 2020, C3.ai (AI 1.06%) made its debut on the public markets with a lot of hype, trading at a market cap of $15 billion. It worked to be an artificial intelligence (AI)-themed stock before the AI revolution took hold a couple of years later. Since the IPO, however, the stock's price has fallen 84% from all-time highs, putting in a disappointing performance for shareholders. If you had invested $1,000 in C3.ai at all-time highs, ...