Typically this is not true. When public companies buy their own stock, this is considered a very positive signal. Apple could do most anything they want (including buying most any company) with their cash hoard.
[1] https://www.bloomberg.com/news/articles/2017-04-18/ibm-misse... [2] https://seekingalpha.com/article/3977909-ibm-bought-155-bill...
Of course I'm not saying IBM is right, or undervalued. If profits are falling a 12% yield might be a 6% yield before you know it, that's why valuations are more complex than my simplistic example. And many companies do buybacks to juice stock prices for the execs options, regardless of value, so it's not a grant signal.