ICBC usurped Citigroup this week when a dramatic surge in the value of its shares made it the biggest bank in the world by market capitalization.
According to statistics from Reuters, on Friday ICBC's Shanghi-listed A shares were worth 5.75 yuan at the close of trading - equating to a market capitalisation of $254 billion.
Meanwhile, on the same day Citigroup's shares closed at $50.73, giving it a market capitalisation of $251 billion.
Fuelled by the booming Chinese stock market and recent healthy profit returns, ICBC's shares have now gained 15 per cent over the course of the last month.
However, Citigroup remains significantly more profitable than ICBC, with income of $90 billion compared with the Chinese bank's income of $24 billion.