IMF Executive Board has approved China's RMB inclusion in the SDR, effective on 1 October 2016. This might raise RMB inflows by USD 31bn, if the total allocation of SDR currently is USD285bn, with RMB's weight at 10.9%. 

This is a modest amount when compared to China's FX flow magnitude. Related transactions are likely done between China's central bank and IMF for several months, indicating direct influence on RMB and FX market should be material.

RMB inclusion in IMF's SDR may help increase demand for RMB denominated assets from other central banks and global fixed income fund managers, over a long term.

"Our FX strategists estimate that central banks already hold around USD80bn in RMB reserves - assuming RMB eventually reaches a similar share as GBP & JPY, the additional demand could be about US$370bn", says Bank of America in a research note.