"They have no vision. What they've evolved into is a company that does [arbitrage] on acquisitions. It's stock buybacks. Who is IBM anymore?" Cuban asked in a "Squawk Box" interview.
In response to Cuban's comments, IBM said via email to CNBC: "When it comes to investing in the business and returning money to shareholders, IBM has done both."
Cuban said the old Big Blue used to have recognizable products.
"They specialize in financial engineering," he said. "To me, that's not a future." He noted that Warren Buffett is a big IBM investor, and said he's a big fan of Buffett, but not of IBM.
In its response to Cuban, the company said: "IBM will accelerate our growth strategy, creating a dedicated cloud business and specialized units to serve industries and professions being transformed by data and analytics. IBM will also continue to return money to shareholders, in addition to maintaining our commitment to R&D and to invest in our business. It is all part of our commitment to delivering higher value to our clients."
Shares of IBM has been under heavy pressure this week after its big earnings miss on Monday. It moved higher on Wednesday. (For the latest stock price, click here.)