"Good on earnings is not good enough," says Jeffrey Small in previewing the string of Mag 7 earnings reporting Wednesday and Thursday. He argues guidance is the more important metric. That said, he sees most of Big Tech as a buy, saying, "we may not see prices like this" for a long time again. Jeffrey's top picks in the Mag 7: Nvidia (NVDA), Amazon (AMZN), and Alphabet (GOOGL).