argenex SE (ARGX) shares rallied 4% in the last trading session to close at $548.49. This move can be attributable to notable volume with a higher number of shares being traded than in a typical session. This compares to the stock's 6.1% gain over the past four weeks.The stock rallied as optimism grew over the company’s marketed product, Vyvgart Hytrulo (efgartigimod), which is approved for treating adult patients with generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy ...