Robusta coffee futures in London are heading for their largest weekly increase in more than 20 years, according to market data compiled on 15 August. Traders say prices have been propelled by heightened concerns over tight supplies from the world’s two biggest robusta-producing countries, intensifying worries about the availability of beans for roasters and instant-coffee manufacturers. The supply shortfall has been attributed to weather-related disruptions and logistical bottlenecks in the major growing regions, keeping buyers on edge and prompting a rush to secure shipments. The sharp rally underscores the vulnerability of the global coffee market to shocks in the robusta segment, which accounts for roughly 40 % of total coffee output and is widely used in mass-market blends.