In the last second of trading on Friday something unprecedented happened to Apple's shares which saw the value decline to a 52 week low of $439.88.

"It looks like a very premeditated unloading of some 800K shares (some $350 million worth) of AAPL in the last second, with the full knowledge it was shake the market," writes Tyler Durden for Zero Hedge.

"Why anyone would want (or wait until the very last second) to do that, while covering the offsetting ES short in the pair trade, to ramp the market into the close, is anyone’s guess," he adds.

Durden has published Nanex charts indicating trades of 800,000 Apple shares worth almost $300 million executed in 17 second intervals. Durden suggests that the trade was done "with the full knowledge it was shake the market".

While there may be no conspiracy, recent occurrences have made us suspicious of AAPL activity on the NASDAQ. As we wrote recently, call options written this summer were due to expire on 19 January and the Apple share price closed at exactly $500 that Friday.

There is a suggestion is that this was "a premeditated flash dump" enable by high frequency trading algorithms, reports AppleInsider.

Algorithmic trading is widely used by investment banks, pension funds, mutual funds, and other buy-side (investor-driven) institutional traders, to divide large trades into several smaller trades to manage market impact and risk. It could simply be that a mass sell off was triggered when AAPL fell to a certain price.

Exxon Mobil back at number one

As a result of the mass sell off, Apple has lost its position as the most valuable publically traded company in the world.

Back in August 2011 Apple overtook Exxon as the most valuable company in terms of market cap. Now, following Apple's recent slide Exxon has regained its position at the top with a market cap of $418.23b compared to Apple's $413.07b.

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