One month ago, when DJIA plunged 666 points, I posted that DJIA will have good support from the 100-day SMA line at 23982 then. DJIA has jumped up and down like a yo-yo since then - with more news on the Russian collusion and more Trump Tantrums - and yet this support at 100-day SMA line still holds. Last week we had another Trump Tantrum - the steel and aluminium tariff - and the support seems to kick in again. There is now signs that the opposition to the tariff is gathering strength and Trump is trying to find a way to save his face (maybe the Mexicans have to pay again).
Back to the chart; look out for the 100-day SMA line support at 24470 now, and the uptrend line support at 23700. If both of these supports failed, you should be worried. Of course, that's not to say that these supports will not break. They are still intact and the market may still come back up.
Chart: DJIA's daily chart as at Mar 5, 2018 (Source: Stockcharts.com)