It’s rare to see a big bank undercut its mortgage competitors so publicly. Most of the time they do it stealthily with “discretionary rates” that are only offered to the bank’s best customers. Not this time. BMO has declared war with a new 3.75% five-year fixed rate. The other big banks are advertising 4.09% for their “special offer” rates. BMO’s promo, however, is 0.34 percentage points lower, and a juicy 1.64% off posted rates!