Stock went ex-dividend today which probably caused some selling. There also seems to be a seller of size overhanging the stock over the past few trading days. Also, the group has been a little weak(as has the market), as some of the other REITs have not reported numbers quite as good as the market may have been hoping for (though not counting on).
My guess is that we have seen the low to this pullback and we go back up from here as the buying demand overtakes this temporary supply. The stock at current yields 7.5% which is much higher than its peers and is very attractive still, compared to alternative investments.
I think we go above $33 within the next two weeks, once good earnings come out, and MAA continues to catch-up to the rest of its peer group -- many of which are yielding 6%~.