The Santa Claus rally is proceeding full steam ahead.

The Dow Jones industrial average is up 4.5 percent over the last four days of trading, which is more than double its rise for the year.

The broader average of the S&P 500 index has risen 5 percent since Dec. 20, and that power move brought the index positive for the year.

A Santa Claus rally phenomenon usually occurs during last 10 trading days of the year, along with the opening week of the new year, where trading volumes are lighter and there’s a bias to raise prices to “window dress” returns for fund managers.The rally continues into the new year due to inflows of new pension money from 401(k)s and IRAs buy into equities.