If you are seeking the answer why has the SPX500 stopped at this strange area and stucked, I got the answer :)
The golden number is a key this time as almost always in technical analysis. This two lines corresponds with 1.618 of two different market moves:
2120 is the level of 1.618 extension of the previous bull run ended in late 2007
2072 is the level of 1.618 extension of the last bear run started right after.
So what?
Notice that 2120 is a very strong resistance tested many times and it is placed exactly on 1.618 of the last bull run. This place is highly probable to be the top of the current 7 years bull run in my opinion. But if resistance will not hold the price this level will be very strong support for prices to attack next important 1.618 level around 2300.