Shares of Indaptus Therapeutics Inc. /zigman2/quotes/204811863/composite INDP +1.31% nearly tripled on massive volume in midday trading, to bounce off the previous session's record closing low, after the developer of treatments for hepatitis and HIV announced the allowance of a patent for its platform technology. The stock was up as much as 307.8% at a six-month high of $28.83 before paring gains to be up 184.3%. Trading volume exploded to 119.2 million shares, compared with the full-day average of just 227,600 shares. The stock was the biggest gainer and third-most active on major U.S. exchanges. The company said before the open that its patent titled "Methods of Treatment of Infections Using Bacteria," provides broad protection for the application of the company's platform technology alone and in combination with standards of care for the treatment and inhibition of hepatitus B virus and human immunodeficiency virus (HIV) infections. "This notice of allowance gives us the optionality to confidently pursue our technology in viral diseases and/or to partner it for further development," said Chief Executive Jeffrey Meckler. The stock has now gained 45.7% year to date, while the iShares Biotechnology ETF /zigman2/quotes/206189322/composite IBB +0.33% has tacked on 13.2% and the S&P 500 /zigman2/quotes/210599714/realtime SPX +1.42% has advanced 19.0%.