Shares in Argent BioPharma Ltd (LSE:MXC, OTC:RGTLF, ASX:RGT) dropped 43% after the company announced plans to delist from the London Stock Exchange (LON:LSEG) (LSE).
The decision comes as part of efforts to reduce costs and simplify administrative processes.
Argent will cancel the trading of its shares on the LSE by December 31, focusing instead on its primary listing on the ASX and the OTCQB Venture Market in the United States.
It has promised updates for investors on how their holdings will remain tradable.
In early trading, the stock was off 6.64p at 8.86p.