Shares of Waitr Holdings Inc. WTRH, +49.10% shot up 45.4% on massive volume in afternoon trading Wednesday, to bounce off a 19-month closing low in the previous session, after Morgan Stanley disclosed a 10.3% stake in the company. Trading volume ballooned to 155.9 million shares, enough to make the online ordering technology platform company’s stock the most actively traded on major U.S. exchanges, and well above the full-day average of about 4.9 million shares. In a filing with the Securities and Exchange Commission late Tuesday, Morgan Stanley said it owned 12.13 million shares of Waitr stock, which would be enough to make the bank and brokerage Waitr’s largest shareholder, according to FactSet data. In Morgan Stanley’s latest 13-F filing with the SEC in August, the broker said it owned just 807,195 shares as of June 30. On Tuesday, the stock had closed at 80 cents, the lowest closing price since March 2020. Even with Wednesday’s rally, the stock has still tumbled 58.1% year to date, while the S&P 500 SPX, +0.29% has gained 16.0%.