 Shares of NOV Inc. NOV, -3.19 dropped 3.4 in afternoon trading Friday, after BofA Securities analyst Chase Mulvehill swung to bearish from bullish on the oil services company, citing valuation and concerns over the negative impacts of Russias invasion of Ukraine. Mulvehill double downgraded NOV to underperform from buy, even as the stock price target was raised to 22 from 18. 