As Venzen's article explain:

At the time of writing, the Bitstamp exchange price has entered a holding pattern around $575. Additional downside seems inevitable, and chart analysis suggests that the current wave down may be the last. However, it may also be the strongest wave of the current decline.

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And:

For now, the primary target of decline is $525, with further analysis keeping an eye on how price negotiates way point $556.

People that trade bitcoins on a regular basis, either by day trading, bots, or going long, tend to follow the different analysis and inputs which in the end makes the price move. If the price falls below a so-called "support level", more people may sell their bitcoins because they fear it may fall even lower. Bots however, that are made by humans with fear, got a "stop-loss" mechanism that tells them to start selling bitcoins if the price falls below a certain level.

Most merchants that accepts Bitcoin like Dell, Expedia, Overstock, and so on, immediately sells their bitcoins to receive the correct amount in USD instead. This can cause a downward sell pressure that will make the price fall if the buying capacity is below the selling capacity.

Dear Bitstamp customers-please make sure you use our updated banking details when sending your transfer to Bitstamp.

? Bitstamp (@Bitstamp) August 13, 2014

This could have caused some uncertainty regarding whether or not the popular Bitcoin exchange may be being pushed towards regulation or a shut down.