Meanwhile, six stocks started buyback mandates in November. Catalist-listed HC Surgical Specialists, a medical services group which focuses on endoscopic and colorectal procedures, led the buyback tally by picking up 459,900 shares for nearly S$321,000. GK Goh Holdings, Japan Foods Holdings, Kim Heng Offshore & Marine Holdings, Mun Siong Engineering and USP Group also began buyback mandates. All six stocks conducted multiple buyback transactions in November, the SGX My Gateway report noted. Share buyback transactions involve share issuers repurchasing some of their outstanding shares from shareholders through the open market. Once the shares are bought back, they are converted into treasury shares and are no longer classified as outstanding. Companies buy back their own shares for a variety of reasons, from ownership consolidation to taking advantage of undervaluation.