An analyst upgrade lifted shares of the online real estate brokerage.Shares of Redfin (RDFN 3.27%) were moving higher again today after the online real estate brokerage got an upgrade from a Wall Street analyst.It was the latest piece of good news for Redfin, which has responded favorably to expectations that interest rates will come down at the Federal Reserve's next meeting later this month.As of 11:21 a.m. ET, the stock was up 7.8% after gaining as much as 15.8% earlier in the session.Redfin's breakout c ...