Bank of America Global Research discusses its expectations for tonight's BoJ policy assessment.

"Policy assessment will result in modest tweaks aimed at making YCC+QE more sustainable given the need for prolonged easing. Expect: 1) Flexibilization of ETF buying; 2) Slight widening of 10yr tgt band; 3) Measures to address reversal rate concerns,"BofA notes. 

"The BoJ's willingness to marginally widen the 10-year trading band and steepen the curve over time could soften the upward pressure on USD/JPY from the widening of US-Japan interest rate differentials, but the decision to widen the 10-year trading band by 5bps tomorrow is unlikely to have a significantly positive impact on JPY," BofA adds.