The company was having problems with equities, options and cryptocurrency trading shortly after markets opened and wasn't ready until an hour later.
Cramer also said that, by the time the market closes, we could be waving goodbye to the bull market investors have enjoyed for more than a decade.
Morgan Stanley, JPMorgan, Bank of America, Goldman Sachs and Citigroup have triggered contingency plans, sending staff home and splitting trade teams.
Some Trump officials see the moment as a chance to finally deliver on promises including border restrictions, isolating China and broader tax cuts.