The point here isn't so much to say, "Ah, prices are extreme and this is a top". Barring a market top, the extreme move from March, 2009 is indicative of two things: 1) the easy gains are behind us; and 2) the indices will likely move sideways to higher but in a more choppy fashion. If a market top comes out of this consolidation, it is likely to develop over the next several months. In general, market tops are affairs; market bottoms are events.
The S&P500 is now 15.39% above its simple 40 week moving average, and this is the highest value since April, 1999. Figures 1 through 5 are weekly graphs of the S&P500 going back to 1970, and the indicator in the bottom panel looks at the current price relative to the simple 40 week moving average. The black vertical lines highlight when price got more than 15% above the simple 40 week moving average, and this is would be when the indicator in the lower panel got above the maroon colored horizontal line .
Figure 1. S&P500/ 2002 to present
Figure 2. S&P500/ 1997 to 2001
Figure 3. S&P500/ 1986 to 1990
Figure 4. S&P500/ 1981 to 1985
Figure 5. S&P500/ 1971 to 1976
For the record the NASDAQ 100 (symbol: $NDX.X) is now 21% above its simple 40 week moving average, and this is the highest reading since September, 2003. The Russell 2000 (symbol: $RUT.X), prior to today, was 20% above its simple 40 week moving average, and this is the highest value since January, 2004.