Most major world markets are trading lower, and U.S. stock futures are dipping into negative territory.
Here are 4 tips for today's trading. This will help you decide where you should invest and what to look for:
1. Siege in Paris
Three terrorist suspects were killed in the Paris suburb of Saint-Denis during a major security operation linked to the deadly attacks that rocked the French capital five days ago, a police source said. A woman killed herself at the scene by activating a suicide belt, and five police officers were wounded during the raid.
France's CAC 40 benchmark index fell about 1% in morning trade. Other European markets also began the day with losses.
An international soccer match between Germany and the Netherlands was canceled after German police said they received "concrete intelligence" about plans for a bomb attack inside the stadium.
And two Air France (AFLYY) flights headed from the United States to Paris were diverted Tuesday because of bomb threats. Both landed safely. Shares in the carrier fell about 1.2%, while International Airlines Group -- the parent company of transatlantic rival British Airways -- fell 2% in London.