These companies have invested billions in AI and could be attractive buys after a sell-off.Tech stocks have taken a deep dive, with the Nasdaq-100 Technology Sector down 10% in just five days. Fears of a recession triggered a major sell-off, with seven of the most valuable tech companies losing a combined $1 trillion in market value on Aug. 5.As a result, now is an excellent time to bulk up your portfolio with companies active in lucrative fields like artificial intelligence (AI). Despite the market downtur ...