The Dow Jones Industrial Average fell on Monday, and recent weakness has so impacted the blue-chip average that all of the Dow's 30 components are below a closely watched short-term technical level. The average DJIA, +0.51% fell 2.9% to 23,412 on Monday. It has dropped 4.6% over the past month, and it is down 12% from an all-time high hit earlier this year. With the declines, all of the blue-chip components are below their 50-day moving average, a level that is often viewed as a gauge of short-term momentum in an asset. Breaking decisively below it can signal deeper losses ahead. The Dow itself hasn't closed above its 50-day since March 9. The S&P 500 SPX, +1.05% fell 3.1% on Monday while the Nasdaq Composite Index COMP, +1.71% was down 3.5%.