BSE Ltd.’s shares extended gains for the fourth consecutive session to trade at record levels above the Rs 2,000 mark as higher transaction charges continue to drive rally.Shares of the bourse, which listed in 2017, jumped over 3% on Wednesday. The stock has surged over 250% or 3.5 times year-to-date. The exchange had announced a buyback price of Rs 816 per share in July. However, as the shares spiked, it raised the buyback price to …