If you are a REP holder, there are some things you MUST do for a fork to not lose your REP.

Before a fork starts

Before a fork starts, REP holders still have to be actively involved so that they don’t lose the value of their REP. The minimum involvement necessary to avoid permanent losses of REP is to check monthly to see if a fork occurs.

Forks last for 60 days, so it is strongly recommended that all REP holders “check in” on the project at least once a month to make sure that no fork is underway or they risk losing all of their REP.

The process of “checking in” just means open the Augur UI or ask around (Discord, Twitter, Reddit, etc.) and see if a fork is underway. If no fork is underway then you can go back to passively holding for a month until your next check in without risk of losing your REP.

Useful links for checking if a fork occurs are:

By the end of a fork

REPv1 holders MUST convert their REPv1 to REPv2 before 60 days have passed since the fork started, because REP in the parent universe can be migrated to only its child universe and once the fork is complete migration into a child universe is no longer possible!

That means they have to follow the chain of universes. For example, forks occur in the following order:

universe A → universe B → universe C

and REP exits in the universe A, it has to be migrated as follows:

universe A → universe B → universe C

It cannot skip universe B.

Figure 1. chain of universes

After starting a fork (60 days)

REP holders needs to pick a side and migrate their REP to the child universe they believe aligns with reality within 60 days from starting a fork. After 60 days from starting a fork, REP in the parent universe are locked and can not be migrated to the child universe permanently. The 60 days starting from the start of a fork is called the forking period.

Figure 2. forking period

However, the choice should be considered carefully, because migration is one-way; it cannot be reversed. REP cannot be sent from one sibling universe to another.

Figure 3. directions of migrating

What if REP holders don’t wish to join in the fork?

They may sell their REP before the fork is over, but beware that if many people exercise this strategy the price of REP may drop leading up to the fork and then rebound in the truth universe after the fork, this could be a costly strategy.

Is there any reward for migrating REP to a child universe?

No. If you migrate your REP during the forking period, there is no reward for that. However, if you staked your REP on the forking market’s outcome before the fork starts, you will receive a 40% ROI on your stake in the child universe where your staked REP migrated.

In other words, there is possibility only for the REP participated in a dispute to receive a 40% ROI. The REP migrated during the forking period cannot receive any reward, even if the child universe which the REP migrated to is the winning universe.

There is no reward for migrating REP. But there is a severe panishment, that your REP cannot be migrated to any child universe, for not migrating your REP within the forking period.