Dow Jones plunges over 200 points, erasing gains for July E-mail Tweet Facebook Google Plus Linkedin Share icons by Tom Huddleston Jr." itemprop="author" class="article-byline-author"> Tom Huddleston Jr. @FortuneMagazine 2:28 PM EDT Geopolitical worries are weighing on investors Thursday, and they have driven the Dow Jones industrial average down more than 200 points in afternoon trading, leading a market retreat that could leave the blue-chip index down for the entire month of July. In addition to the Dow’s 1.3% drop below 16,660 points, the S&P 500 is down 1.5%, while the Nasdaq dipped nearly 1.8% in afternoon trading. As things stand now, both the Dow and the S&P 500 are set to finish July down slightly, erasing all gains from a month that saw the Dow cross the 17,000-point mark for the first time ever and hit multiple record highs. The Chicago Board Options Exchange Volatility Index (VIX), known as the “fear index,” is up more than 20%, hitting a multi-month high. Contributing to the market’s retreat: news late Wednesday that Argentina’s credit rating has been downgraded to selective default by Standard & Poor’s. The country’s second default in 13 years sent its Merval stock index plummeting nearly 7% Thursday afternoon. There are also lingering questions over how the latest round of sanctions on Russia issued by the U.S. and Europe will affect the global economy, including the energy markets. Exxon Mobil XOM , which has a multi-billion dollar partnership with Russian company Rosneft, saw its stock drop 2.9% on Thursday. If the day’s losses continue to the close of trading, this could be the Dow’s first 200-point drop in almost four months.