Shared or Isolated

Kraken: Previously you could only run one trader at a time on Kraken, because Kraken has no sub-accounts. The trader now supports a shared account. On a shared account, such as Kraken, it splits the available euros or dollars across the linked traders. It takes into account the trader type (EUR or USD), how many traders are linked to the account, and any limits on those traders. Everything happens automatically, and multiple traders no longer get in each other’s way.
Shared only

Bitstamp: On Bitstamp you can choose whether you have a shared account or an isolated account. Isolated is preferred, because it keeps everything neatly separated on the exchange itself by running each trader in its own sub-account.
Shared or Isolated

Set this up yourself: Create traders.

Benefit: Isolated keeps bitcoin and FIAT (usd or euro) separate per trader on the exchange itself. Shared is needed when you work with Kraken.