Qatar has liquidity..lots of cash...debt is covered in essence against gas/oil production..year on year real growth...attractive for inward investment..conservative oil/ gas prices used for budgeting..

Massive purchasing of prime assets abroad to compensate for future diversification away from gas and oil.

Small populous. High GDP. = Rich.

Countries with high GDP's as total output tend not to have as much liquidity; high populations = high internal costs. Higher debt, massively higher internal costs and not as liquid hence bangladesh is relatively poor compared to Qatar despite the high GDP.