Getty Images Apple CEO Tim Cook and Amazon CEO Jeff Bezos.

Facebook, Apple, Amazon, Netflix, and Google have lost $US728 billion off of their value in six weeks.

That’s more than the gross domestic product of Saudi Arabia.

Amid fears of a slowdown in iPhone sales, Apple has been hit hardest. Facebook, though, is on course for its longest-ever losing streak.

It was another dark day in the markets for America’s biggest tech companies.

The so-called FAANG firms – Facebook, Apple, Amazon, Netflix, and Google – all finished Monday in the red as the sell-off deepened. It was the continuation of a downward spiral that has run for weeks.

In fact, since Apple hit a high of $US232 a share on October 3, giving it a market cap of $US1.16 trillion, the FAANG companies have lost a combined $US728 billion off of their value, according to numbers crunched via Macrotrends.

That’s more than Saudi Arabia’s gross domestic product, which is$US683.83 billion, according to World Bank figures. This in itself is something of an irony, given the kingdom’s desire to emulate Silicon Valley.

During the six-week sell-off, Apple has been hit hardest. Amid fears of a slowdown in iPhone sales, Apple’s market cap tanked by $US231.06 billion, to $US929.32 billion on Monday.

How much has been wiped from the value of the FAANGs since October 3:

Apple : $US231.06 billion

: $US231.06 billion Amazon : $US220.67 billion

: $US220.67 billion Google : $US138.22 billion

: $US138.22 billion Facebook : $US89.95 billion

: $US89.95 billion Netflix: $US48.11 billion Total: $US728.01 billion

Amazon was next in line, while Facebook’s declines have been significant as it remains dogged by controversy over data breaches, election interference, and crisis mismanagement.

Mark Zuckerberg’s company on Monday hit its lowest level since February 13, 2017. It is now on course for a third month in the red, which would be its longest-ever losing streak, according to CNBC.

The tech pummelling has also dragged down the wider market. The S&P 500, the Dow Jones Industrial Average, and the Nasdaq dropped by 1.66%, 1.56%, and 3.26% on Monday.

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