shares of paxmedica inc were trading higher friday after the company reported share purchases by its chairman and a shareholder at 1111 am et the companys shares were 38 higher at 483 on nasdaq volume at the time topped 271 million shares above the stocks 65day average volume of just over 5 million shares after the bell thursday paxmedica said founder and chairman michael derby purchased 95000 shares at 525 apiece the transaction brought his holding to 77 million shares the company said in a filing with the us securities and exchange commission shareholder tardimed sciences llc purchased 95000 shares at 525 each bringing its holding to 73 million shares paxmedica said mr derby is the founder and managing partner of tardimed paxmedica priced its initial public offering of about 15 million shares at 525 each the biopharmaceutical companys shares debuted aug 26 and finished the day with a 49 gain the share price has ranged from 280 to 1048 since the stock began trading