0408 GMT - China's AI sector is showing a "barbell profit structure," with the strongest economics concentrated at both ends of the value chain, according to BofA Securities in a research note. Strategic hardware bottlenecks such as AI accelerators, semiconductor equipment, foundries, and memory are likely to benefit from high entry barriers and capital intensity, the bank points out. Cloud service providers and large AI platforms enjoy other benefits, such as scale advantages and rich user use, it says. By contrast, standalone large language model labs and physical AI manufacturers face more intense competition, which limits their pricing power and profitability, the bank says.