[SEOUL] Investors in Samsung Electronics Co are watching their holdings plunge as new Galaxy smartphones get a lukewarm public response. With US$55 billion in cash, the company may be poised to offer consolation. Analysts expect the world's biggest smartphone maker to buy back shares as early as this month in an effort to return some value to stockholders. Removing more than US$1 billion of stock from the market could prompt shares to rally by as much as 20 percent, according to the top-ranked analyst covering Samsung, potentially erasing their declines this year. Samsung has lost about US$25 billion in market value - roughly equivalent to a Nintendo Co - this year as sales of the S6 and Note 5 devices sputter against new models from Apple Inc and Chinese makers. A buyback would be just the second in eight years and may take the sting out of sliding market share and sales projected to hit their lowest since 2011.