The world’s biggest investors have much less money invested in developing nations than in developed ones, and the amounts are falling, not rising. But one sovereign wealth fund is swimming determinedly against the tide.

With around $20bn under management, the State General Reserve Fund of Oman — a Gulf nation with a population of 4.4 million at the southeast corner of the Arabian peninsula — is small compared to the giant oil funds of its neighbours in Abu Dhabi and Saudi Arabia.