A false tweet which was apparently from the Associated Press saying there had been explosion at the White House, sparked a brief bout of upheaval in financial markets on Tuesday (April 23).

Volatile price moves ricocheted through markets for stocks, bonds, currencies and commodities at around 1:00pm EDT (0500GMT) when the tweet surfaced saying President Barack Obama had been injured.

The move in stocks described by one futures trader as "pure chaos," briefly wiped out about $140 billion in U.S. market value. When it became clear that the tweet was fake, equities rebounded and more than recovered the losses - the S&P 500 index ended up 1.04 percent.

What jolted investors and traders was the source: The Associated Press, which describes itself as "one of the largest and most trusted sources of independent newsgathering." The tweet was sent from its "verified" Twitter account.

The impact quickly started to wear off as traders began to question the veracity of the tweet. Within a few minutes, the AP had told news organizations that the report was "bogus".

The damage seems to have been done however, as it appears to have inspired some soul-searching among traders who rely on Twitter as an important source of information.

Presented by Adam Justice