In addition to the Dow's plunge, the S&P 500 fell 3 percent, also turning negative for the year, and the Nasdaq Composite fell by 4.4 percent.
Overall, the Dow has declined by 7.1 percent in October, S&P by 8.9 percent and the Nasdaq by 11.7 percent.
The share values of several tech giants all fell on Wednesday, including Facebook (down 5.41 percent), Amazon (down 5.91 percent), Google's parent company Alphabet (down 5.17 percent), AT&T (down 8.08 percent) and Netflix (down 9.4 percent).
AP reported that more than 100 S&P 500 companies are expected to report strong third quarter results this week, and every sector except communications services is expected to show growth. AT&T, however, reported a 7.5 percent drop in quarterly results.
"An increasingly murky macro picture is clouding the 2019 earnings outlook, leaving investors to largely shrug off a solid start to the third quarter earnings season," Alec Young, managing director of global markets research at FTSE Russell, told CNBC.
While stocks rallied on Tuesday, industrial manufacturing giant Caterpillar reported a 7.5 percent decrease in quarterly earnings that day, causing a 10 percent fall in its stock values, and 3M conglomerate fell by 4.4 percent, which FBC Securities chief market strategist Jeremy Klein told CNBC still weighed heavily on markets today.
"[There's] carnage pretty much everywhere," Klein said. "I think tech is just caught up in it today."
