The account is linked to the performance of four asset classes – developed market equities, emerging market equities, property and gold. Deposits are split equally between these assets, exposure to which is gained through indices.
Natwest said the account links to the asset classes when markets are rising, but switches to cash when they fall.
Account performance is capped at 8% in any month for sterling and dollar accounts and 7% for the euro option. The account is also fully capital protected if held until maturity, which is April 2016.
The Jersey-based bank said the enduring popularity of the product was evidenced by the fact this was its fifth issue since its original launch in 2008 and that the number of accounts issued had increased by some 50% in each of the following years.
It has a minimum deposit of £10,000.
Ashley Taylor, head of international wealth managers at NatWest IPB, said: “The account was originally designed to simplify portfolio diversification and asset allocation by using a rule-based strategy that allocates their deposit carefully.
"Having received such a continued positive response to the range from our customers we are confident it will continue to be a successful strategy.”