Pokémon GO: How to Trade Evolution - Ultimate Guide

"Before you know how to trade evolution you must take into account and know that it is a mechanic called" Trade Evolution "detected by some Pokémon in order to evolve, you must take into account that this is the only way of evolution for Karrablast, Shelmet, Graveler, Chaser, Boldore, Gurduur, Kadabra and Machoke.

Evolution trading is quite simple, have the second form of Pokémon in your collection that a friend will ask a friend to trade with you.  By making the trade your Pokémon will go with your friend and will be given a lower candy cost to evolve. 

You should keep in mind that when you trade a Pokémon, you can only do so once, so when you trade with a friend, your friend will keep that Pokémon.  So your friend will have to send the exchange if you want to lose the cost to evolve the exchanged Pokémon.  So be very careful what you trade and what you get in return, don't be sorry later.

The great thing about this evolutionary mechanism is that it can really help Trainers looking to save candy with these Pokémon that want to use it to level up and make them stronger.