Mediclinic has rebuffed a £2bn (R38bn) takeover offer from a group of investors that includes its biggest shareholder, Remgro, with its shares having their best day in about eight months as equity traders bet that the Johann Rupert-chaired investment heavyweight is likely to return with a higher bid.

Along with shipping company MSC, in late May, Remgro offered 463p a share for the 55.4% it does not already own in SA’s most valuable hospital group, which is also listed in London...