Capital One increased the APY on its money market accounts from 4.55% to 4.75%. The two money market accounts are the High Yield Money Market account (the no minimum savings account which provides good ACH linking) and the Money Market account (has a $100 mininum, check writing but no ACH). Although Capital One hasn't been a rate leader, it has done a decent job at staying competitive. The last rate hike was on May 3rd when Capital One increased the rate from 4.25% to 4.55% APY.
Capital One's Costco Money Market account also had a rate increase, although it wasn't much. The new rate is 4.80% APY (up from 4.77%). This Costco money market account averages about 0.20% over the standard money market account rate. So it's likely that the rate will increase over the next few weeks. The special $50 sign-up bonus for Costco Executive members is still available (see post).