As such, we find ourselves well into the lowest rates in more than three years, even if the pace of improvement is lagging the drop in US Treasury rates.  For what it’s worth, 2016’s mortgage rate improvements have kept up with Treasuries much better than in 2012–the last time markets were moving abruptly for somewhat similar reasons.  The average lender is now down to 3.5% in terms of conventional 30yr fixed quotes for top tier scenarios.  Further improvements from here will be hard fought, so it makes good sense to consider locking to avoid a temporary pull-back ahead of next week’s vote on the British referendum on remaining in the European Union.