Shares of IBM (IBM - Get Report) have been volatile so far Tuesday. The stock beat on top and bottom line earnings estimates but once again sales declined year-over-year. The stock, which initially started higher at the open, has since dropped into negative territory, then rebounded back to flat on the session.

Perhaps this is because of the "great" analyst Toni Sacconaghi, TheStreet's Jim Cramer, co-manager of the Action Alerts PLUS portfolio, said on CNBC's "Stop Trading" segment.

In Sacconaghi's recent research note on IBM, he did not give investors comfort over the most recent quarter, Cramer said, explaining the company's organic revenue growth decelerated. Now it brings into question whether the company can hit estimates in the second half of 2016.

Cramer reiterated that Sacconaghi is a "very, very good" analyst who does rigorous research on each of the stocks that he covers.

At the time of publication, Cramer's Action Alerts PLUS had no position in companies mentioned.