Carl Quintanilla and Jim Cramer discuss the massive swings in stock. Wall Street struggles to recover from its worst day in more than 30 years despite signs of potential further stimulus and progress on a possible treatment for the coronavirus. Overnight, Dow futures reached their "limit up" level before rolling over, falling below 20 thousand. Cisco Chairman and CEO, Chuck Robbins, commenting on the virus and how it's impacting his company. Plus, ServiceNow unveiling 4 new emergency apps in the wake of the pandemic, the CEO joins the "Squawk on the Street" gang to discuss.