Shares of Memory Pharmaceuticals, the US biotechnology group, surged 42% in early trading on Nasdaq, after the pricing of its initial public offering was delayed for two weeks and the cut to $7 from an original range of $13-$15.

By the end of the first full day of trading on Tuesday, the price rose to $9.95, valuing the group at $50m (€41m). UBS and SG Cowen were joint bookrunners for the flotation which raised $35m through the sale of five million shares.