Wall Street suffered its worst day of trading in 19 months as disappointment around earnings from Tesla and Google challenged the recent big-tech rally.The benchmark S&P 500 index dropped 2.3% as a sell-off triggered its biggest single-day fall since December 2022.The technology-focused Nasdaq retreated 3.6%, its largest single-day decline since October 2022.Shares in Tesla sank 12% after it reported a 45% slump in quarterly profits amid discounting by electric carmakers. Alphabet, the owner of Google and Y ...