Early on in my writing and editing career, I made the mistake of missing a very serious error within a document. Instead of saying millions, which was categorized by “MM,” I sent something to press with a single “M,” standing for thousands, and forced a large client of ours to be less than pleased with the major slipup.

Lucky for me, I brief scolding from my editor was all I really received, and millions and millions of dollars were not lost.

However, according to a CNBC report, the Dow’s horrific plummet today of nearly 1,000 is rumored to be caused by a similar type of mistake.  And, they weren’t so lucky.

According to multiple sources, a trader entered a “b” for billion instead of an “m” for million in a trade possibly involving Procter & Gamble, a component in the Dow. Within the CNBC report, sources leaked information that the firm in firm in question that handled the erroneous trade is Citigroup, which is now -0.14, or 3.35 percent, down to 4.04 per share.

With the spread of debt across Europe, this supposed mishap could perhaps be another trigger to a wave of defaults across Europe and even the world.

The massive selloff, which began shortly after 2 p.m. ET, amplified concerns about the spreading European debt crisis as the approval of austerity measures by the Greek Parliament sparked renewed rioting in Athens.

Hitting a new 14-month low, the euro tumbled today, falling further against the dollar.