The champion of Bahrain All Share Index is BAHRAIN:ESTERAD — it's gained 93.50% over the year.
The weakest component of Bahrain All Share Index is BAHRAIN:ITHMR — it's lost −64.00% over the year.
Bahrain All Share Index is just a number that lets you track performance of the instruments comprising the index, so you can't invest in it directly. But you can buy Bahrain All Share Index futures or funds or invest in its components.