I think that as short-term traders book profits, the longer-term investors are going to step to the plate, so downside risk appears limited. (The could just go higher, but the move since Friday morning is ripe for short-term profit-taking.)
The Nasdaq has immediate support at 1852-1832, then 1803-1770 (1803-1770 is not expected to be tested).
The Nasdaq finished the session in a test of the 1842-1878 level of resistance. Above Nasdaq 1878, the next layer of organized resistance is 1901-1960, with a focus at 1915-1942.
The S&P 500 has a layer of support at 1147-1143, then more substantial support at 1127-1121. The S&P 500 finished Monday's session in a test of the 1150-1162 area of resistance; this is within a broader band of resistance which runs 1150-1174. The next resistance above that is 1190-1206.
With the kinds of readings I am seeing now, I think over the next four to 14 trade days, the Nasdaq should get to (minimum) 1915-1942 and the S&P 500 should get to 1190-1206. Cherney is market analyst for Standard & Poor's