Analyze the situation and remember that every crisis is also an opportunity. Try to think about what kind of change is coming, how people's needs will be affected, if there are any new ways you could apply your skills in, etc. At the same time be careful about big purchases and avoid any impulsive decisions like "omg the stock market is falling, it's the best time to buy .." Remember that even big companies can go bankrupt.
Stay calm and invest into yourself: your health, your education, your social life, your professional skills, your overall happiness. Unlike money, these things never lose their value.
It doesn't even matter how much or little money you have, you can always invest your time and effort into learning something new that may change your whole life. Take care of yourself. Train your body and keep a healthy diet, get enough sleep, try not to get too stressed, meditate or just relax with a good book, movie or music, don't forget to go out, spend time with your friends and family.. all of this doesn't really require that much money. If you can, try to help out people around you, you may be saving their lives.. And remember that this too shall pass.