NEW YORK (TheStreet) -- Jim Cramer answers viewers' Twitter (TWTR - Get Report) questions from the floor of the New York Stock Exchange.

When one viewer asked how long the market is likely to dip if the Federal Reserve raises rates in September, Cramer said Monday that rates would dip for two to four weeks.

He said there are always market participants trying to make a lot of money on a rate hike who make bet on the wrong side and then fail.

Another viewer was looking for insight on 3M (MMM - Get Report), and Cramer said the stock, which is a core holding in his Action Alerts PLUS portfolio, doesn't get enough respect. Cramer added that he's looking to increase the size of his position.

In response to another viewer's question about when to invest in GW Pharmaceuticals (GWPH), Cramer said that unfortunately, if you haven't bought the stock already he can't help you with it now. (Cramer has championed it for a long time.) Cramer did say, however, that Molina Healthcare (MOH - Get Report) looks interesting. He also said that his prediction is that Anthem (ANTM - Get Report) is going to buy Humana (HUM - Get Report) and that Cigna (CIG) will merge with Aetna (AET).

Noting that Home Depot (HD - Get Report) and Walt Disney (DIS - Get Report) reported great quarters, another viewer asked whether these stocks have spent enough time doing nothing and whether investors should buy them now.

Cramer says he advises that investors wait for the next interest rate scare and buy the stocks at that time.

Lastly, Cramer weighed in on Celgene (CELG - Get Report) as the stock has been drifting lower. Cramer acknowledged that the stock has underperformed the group and said that even though he's a believer in the company, the stock will have a difficult time for the foreseeable future.

If you have a stock question you'd like answered by Jim Cramer, make sure to tweet it @jimcramer using #CramerQ.