When do you think the next stock market crash will be?
Stock market crashes are notoriously difficult to predict.  Historically, they have happened after a period of "irrational exuberance" in the markets that cause stock prices to rise to a level that is not supported by long-term economic growth rates.  Typically, there is also some sort of shock, an unexpected event that triggers the crash.   I will not guess at the date of the next crash, but would advise you to be cautious when stock prices have risen quickly in a short period of time that is not accompanied by overall GDP growth.