China"s yuan strengthened on Wednesday, with both onshore and offshore units touching their firmest levels against the dollar in more than three-and-a-half years after the central bank set its daily fixing at a more than six-month high. The People"s Bank of China set the yuan"s midpoint rate at 6.3677 per dollar prior to market open, its strongest since June 1, amid what traders said was strong corporate dollar sales ahead of year-end. Traders said FX settlement demand would continue to boost the yuan, potentially pushing it through the 6.35 per dollar level. "It"s all about dollar settlement, and the yuan will continue to strengthen if the big banks don"t block it," said a trader at a foreign bank. Ken Cheung, chief Asian FX strategist at Mizuho Bank, echoed suggestions that real demand from FX settlement would continue to support the yuan, and noted that a divergence in monetary policy between the PBOC and the U.S. Federal Reserve for now "appears to take a backseat" in driving exchange rate moves, despite a cut to banks" reserve requirements announced this week. read more "The RMB rally could be driven by the USD diversification flow and the inflow to RMB assets would be long term ... which should prove to be less sensitive to the monetary policy divergence and yield differentials. Second, market participants may be still waiting a clearer signal of PBOC"s easing shift," he said. Cheung said verbal intervention by the PBOC to contain appreciation expectations was possible, but actual policy changes remain unlikely. Spot yuan opened at 6.3629 per dollar on Wednesday and strengthened to 6.3515 per dollar, its firmest since May 15, 2018. By midday it had given up some gains to trade at 6.3540, 118 pips stronger than Tuesday"s late session close. Offshore yuan firmed to 6.3509 per dollar, its strongest since May 23, 2018, and was trading at 6.3523 per dollar at midday. A broad dollar index fell to 96.155 from the previous close of 96.283. The yuan market at 4:01AM GMT: ONSHORE SPOT: Item Current Previous Change PBOC midpoint 6.3677 6.3738 0.10% Spot yuan 6.354 6.3658 0.19% Divergence from midpoint* -0.22% Spot change YTD 2.74% Spot change since 2005 revaluation 30.26% Key indexes: Item Current Previous Change Thomson Reuters/HKEX CNH index 102.39 102.31 0.1 Dollar index 96.155 96.283 -0.1 *Divergence of the dollar/yuan exchange rate. Negative number indicates that spot yuan is trading stronger than the midpoint. The People"s Bank of China (PBOC) allows the exchange rate to rise or fall 2% from official midpoint rate it sets each morning. OFFSHORE CNH MARKET Instrument Current Difference from onshore Offshore spot yuan * 6.3523 0.03% Offshore non-deliverable forwards ** 6.524 -2.40% *Premium for offshore spot over onshore **Figure reflects difference from PBOC"s official midpoint, since non-deliverable forwards are settled against the midpoint. . Reporting by Andrew Galbraith; editing by Richard Pullin Our Standards: The Thomson Reuters Trust Principles.