Bidvest said in a statement it now holds 32.03% of , 's second-largest pharmaceutical company, and confirming a Reuters report it had bought the bulk of the record 39 million shares traded on Thursday.
Chilean firm CFR Pharmaceuticals has offered R12.8bn in cash and shares for , a deal that requires approval from shareholders with 75% of at a meeting next month.
Shares of fell 3.27% to R67.70 at 12:50, below Bidvest's cash offer of R70.
Before Thursday's buying spree, Bidvest had held around 9% of .
The 39 million shares traded on Thursday represented a record since 's listing in 2008 and far outstrips last year's daily average of under 650 000 shares, according to Thomson Reuters data.
Bidvest, which first tried for control of in March, has gone to shareholders with a cash offer for 34.5% of . That offer expires next week.
Ingram is due to hold its annual general meeting later on Friday.