Bitcoin dips below $90,000 as AI worries dent risk appetite

By Gregor Stuart Hunter SINGAPORE, Dec 11 (Reuters) - Cryptocurrencies tumbled on Thursday and bitcoin (BTC-USD) fell back below the $90,000 threshold in ​a renewed signal of market jitters as fresh concerns ‌about artificial intelligence profits weighed on technology stocks. Risk sentiment turned sour after U.S. ‌cloud firm Oracle's profit and revenue outlook missed forecasts and executives flagged higher spending - a sign AI infrastructure outlays are not turning profits as quickly as investors had hop ...