Buy Strength, Sell Weakness

If the signals came all at once, we always bought the strongest markets and sold short the weakest markets in a group.
Within a correlated group, the best long positions are the strongest markets (which almost always outperform the weaker markets in the same group). Conversely, the biggest winning trades to the short side come from the weakest markets within a correlated group.
The important thing is to have long positions in the strongest markets and short positions in the weakest markets.
From Way of the Turtle: The Secret Methods that Turned Ordinary People into Legendary Traders by Curtis Faith
For example, forked currencies usually have the same functions as the ones been forked. Obviously, forked currencies are weaker, so long positions for BTC may have more profits while short positions for BCH may have more profits, long positions for ETH may have more profits while short positions for ETC may have more profits.