For its last move in an action-filled year, the Federal Reserve announced it will begin buying its pledged $500 billion in mortgage-backed securities next month.

For home buyers, the timing couldn’t be better.

Because December 31 is one of Wall Street’s most thinly-traded days of the year, low volume is exaggerating the announcement’s impact on mortgage markets.

Mortgage rates are lower this morning.

However, you may not have much time to act.  Few mortgage lenders permit after-hours rate locking and bond markets close at 2:00 PM ET for the holiday.  If you miss today’s Fed-fueled low rates, markets re-open Friday for your second chance.