iphone 7
Phil Schiller, Senior Vice President of Worldwide Marketing at Apple Inc, discusses the iPhone 7 during an Apple media event in San Francisco, California, U.S. September 7, 2016. REUTERS/Beck Diefenbach

Apple announced the release of the iPhone 7 Wednesday, which means those who have not yet traded in their iPhone 6's might soon be out of time. The reason is quite simple: everyone is going to want the newer model, according to electronics trade-in and recycling service Nextworth.

A recent survey conducted by Nextworth found that 55 percent of current iPhone users plan to purchase the iPhone 7 by the end of 2016. That means that a lot of old iPhones will be going back on the market in exchange for the iPhone 7, significantly decreasing the trade-in value of those older models. The decrease in trade-in value after the announcement of a new iPhone model can be as much as 40 percent in just the first few months that immediately follow.

In dollars, that can mean a difference of $100 in value for the iPhone 6 or 6S, so the first few weeks of September are the best time to make a move, especially considering the market was just flooded with new iPhone 6's — Apple's iPhone 6S model was the world's top-selling smartphone in the second quarter of 2016, according to Economic Times.

Nextworth
Nextworth estimates that the drop-off in iPhone 6 value after the announcement of the iPhone 7 will be steep. Nextworth

Apple made a splash with Wednesday's announcement of the iPhone 7 models. The tech company announced the phone via a Tweet that was subsequently deleted, along with every other tweet in the official Apple Twitter's timeline.

The original tweeted touted the new phones' improved camera, water resistant capacity, stereo speakers and longer battery life.

The announcement also confirmed an expected by controversial feature of the new iPhones: the lack of a headphone jack. The move is a pivot on the part of Apple to make the phones thinner and add battery life while also embracing the improvement of Bluetooth technology that is sweeping the headphone industry.

Apple later confirmed its new phone during an event in San Francisco. The iPhone 7 starts at $649 with 32GB and orders start Friday.