This weekend was Poliwag Community Day, and due to an error certain event bonuses ended early. Niantic issued an apology on their NianticHelp twitter account, explaining the compensation for this error.
Unfortunately the event trade bonuses became inactive before 10 p.m. local time, meaning trainers missed out on the extra chances to reroll their shiny Poliwags (or other special trades). As a result there will be additional trade related bonuses to make up for the errors.
Beginning now until August 2, 11:59 p.m. local time, the make up bonuses will be as follows:
This is a great opportunity to swap some shiny Pokémon you need, or try for different IVs on Legendary Pokémon, so be sure to communicate with your friends and local community, and take advantage of this while you can! Three special trades is a very rare bonus, and depending on your time zone, you may be able to get three days of this bonus.