美国银行警告称，股市泡沫风险依然存在，但认为人工智能领域仍有更大的上涨空间。

Group 1 - The core viewpoint of the article is that while the risk of a stock market bubble persists, there is still significant potential for growth in the artificial intelligence sector [1] Group 2 - The warning from the bank highlights ongoing concerns regarding stock market valuations and the possibility of a bubble [1] - The bank expresses optimism about the artificial intelligence industry, suggesting it has greater upside potential compared to other sectors [1]